I did residential security for years before the army. I have also done some commercial, including jewelry stores and one class III dealer, and a huge AAA rated security system with two vaults, etc., etc. Made a bank look like child's play. So I am kind of familiar with this. Security comes in layers, yes, but what layers to get first? Unless you are loaded or very handy, this will be an ongoing process for some time.
For your alarm, hardwire everything you can. Only use wireless as a last resort or as some type of addition. NEVER use a keypad/panel combo, and especially a wireless one. Probably the most important thing about alarms is there really are no good shortcuts. Use in your home the same stuff used in jewelry stores (they have to have the right stuff or their insurance will drop them).
Monitored alarms are great, but if it doesn't have cell (or preferably radio) communications, it won't work except as a local alarm that will notify your neighbors. This may be okay, depending on your situation (not advised, though a local alarm could be your first step). The smaller local alarm companies that do their own monitoring will offer this, but will cost twice as much as say, an ADT or Security Link dealer, who can only offer land line or internet monitoring. All decent burglars, even drunk ones, know to disconnect the phone line first. Cutting it, if installed properly and connected to a land line, will set off the siren. Disconnecting it will not (you can make it do this, but anytime the phone goes down the alarm will go off). So an alarm that is only on a land line with an exposed dmark (that plastic box on the side of your house where the line comes in at) is essentially just a local alarm.
That brings me to sirens. They should be minimum 30 watt horns that warble; interior horns don't cut it either. Use them too if you want, but exterior first and foremost, and if you use the interior, get the "noisy cricket" types and try to install it centrally or in the kitchen area (more reverb with hard floors). These interior horns actually hurt your ears and can make you pee your pants if you aren't expecting it. Some places won't let you use exterior sirens anymore because of proliferation of alarms by home owners that purchased them from dealers that installed them improperly (and some is just statistics --there are more false alarms than real ones). Do not the car alarm type that everyone ignores. The ones that talk are okay, and you can get them in both English and Spanish (one announcement after the other) but not really necessary. Bells are better, but more expensive. They make noise for a greater distance than you would realize. Strobes are handy, but not necessary, unless you can't have the exterior siren, then I'd say get it. They are most efficient when you have close neighbors.
Passive IR motion detectors are a must in every room. Don't use pet motions unless you need one in a shut off room for the dog or what have you. They just aren't as sensitive. There are ultrasonic and microwave, but not worth the price unless you are expecting Bond --James Bond. Glass break sensors are okay, but take a backseat to IR's. It does no good to have an alarm and have an unprotected area, as I could just break into that room and dismantle the rest from there. I wouldn't care too much about your framing or drywall either as speed is of the essence. I've seen them come through the floor and attic, right next to the panel, in an unprotected hallway --then they have all the time to disconnect the system.
Programming the system. These alarms will do much more than you realize. Make sure you get the most out of it by asking questions and reading up on your system. Dealers usually use a standard template and won't change the data entry unless requested. Since most customers don't know what to ask, this rarely happens and they get the template. Oh yeah, and don't use 1234 as a code, and don't use a duress code (code used to turn off alarm and report a hostage situation) that you will forget. For the duress code, use something stupid, or at least easy to recall with a pistol to your head. I've seen a SWAT team deployed in under a minute to a residence in Memphis TN. The daughter of the home owner didn't think what I put in would work. She did when the entry team came though, and called to tell me! Of course a duress code will do you no good if the alarm is not on, so use it when inside, say at night. I know where the burglary happens from the bedroom, so I know where to clear first too.
Which brings me to alarm timers. You don't need five minutes to enter and exit the house. If your installer did his job and programmed it right, it might not be of consequence, provided the entry time isn't too long. But I just use the minimum to get by. Your alarm should be fully armed a few steps out the door. It should go off when you get home no more than 15 seconds in the door (you should have one keypad right next to your entry/exit and preferably one in the bedroom). Note this does leave room for a false alarm, so practice, practice, practice (you've heard this before, right?).
Now to dogs. They are okay. But they are suckers for food, and fall for the old phenobarbital in the peanut butter everytime, unless VERY well trained. And just hope the bad guy, who I will assure you can find some drug that will do the deed, doesn't OD your best friend. Don't depend on them for alarms either. They aren't foolproof, and some sleep quite well. Especially on a double dose of phenobarbital. Think of your dog as something you want to protect, rather than something that protects you. The dog can't roam inside anyway with the alarm set, not one big enough to do harm anyway, because if they don't set off your motion detectors, then the bad guy won't either, will he?
Note that not all alarm systems are created equal. They are similar, but not equal. For instance, a used Radionics panel from 1979 is better than a DSC 1500 from the 90's. In fact, it is one of the best systems out there, and Bosch bought them out and repairs that old stuff to this day. Higher end modern systems are equivalent to the old Radionics. Very good, and equal to the old Radionics, provided you stay away from the lower end models. You can get a good deal on a used panel and keypad online, but you will need someone that can program these panels. They use a special programmer, part of why they are so good (and a pain --if it is a pain in the neck for the installer to defeat, it will work against most bad guys).
Advertise the system. Forget the silent alarm and unadvertised approach unless you really know what you are doing and are setting a specific trap, ie, you've been broken into before and are trying to catch someone in particular. The yard sign is a good thing. Put it right next to the "Posted: No Trespassing" sign if you live on land or off the street, or between that and the camera (real or fake) that is next to your locked gate (yes, a fake camera with a battery powered light mounted out of reach is useful and cheap --seen check cashing places use them in the 90's, although that wasn't a smart application). The no trespassing sign is good since it makes it a misdemeanor to come onto your property, and when you get your cameras later on, just email the cops and prosecuter the picture of the guy casing your lot and --presto! Instant conviction once identified, and a warning that whatever you have isn't worth it. This advertises that you put the effort into protecting your property and that your neighbor who swears by the pit bull is the better opportunity.
Cameras. They have come a long way. You can get a box kit from Costco that is miles better than the good stuff I used to install 15 years ago. I've seen it work wonders, even in jewelry store applications. Not sure if the Costco kit can connect to the alarm system, but it isn't necessary since you don't need a time lapse recorder anymore. And wherever you put the recorder, make sure it is hidden. I won't go more in depth about cameras since this kit will cover 99% of you out there. I will say that cameras take a back seat to the alarm (usually).
That covers some basics. I could write a book on it, but this should suffice to get one going past the crap that the dealer's sales guy will tell you. I need dinner anyways.
If you have specific questions, I would be happy to answer them. Just send a message. But whatever you do, keep your firearms locked up in a steel locker at a minimum and start working on that security system.