Sevengunner - I'm a MD resident, and I've never had an issue with the way you've mentioned - guns unloaded (mags too) enclosed in a case, seperate from the ammo, in the trunk. It's my understanding that as long as the guns and ammo are seperate, and both are inaccessible to the people in the car (like in a closed, latched case) you're good to go. The law is not the clearest when it comes to transport, but as long as you're transporting them as you've described, and don't give the cops a reason to pull you over in the first place, you'll be fine.
Specifically, here's the wording from mdgunsafety.com:
Can I legally transport my regulated firearm to the range?
Yes, provided the handgun is unloaded and carried in an enclosed case or an enclosed holster, and you are transporting the handgun to or from the places listed in section 4-203 of the Criminal Law Article of the Annotated Code of Maryland.
Which leads to the second issue. The way the law is written, there is some disagreement over whether or not it is legal for an individual to stop at any point along the route from their home, to the range/gun shop/gunsmith, etc. This is what the law says in regards to how/where you may transport your guns:
1. To or from a place of legal purchase or sale or repair shop.
2. Between such person's bona fide residences or between his residence and place of business if the business is operated and substantially owned by that person.
3. While engaged in or traveling to and from a "target shoot, formal or informal target practice, sport shooting event, hunting, trapping or dog obedience training class or show."
4. By a bona fide gun collector who is "moving any part or all of his gun collection from place to place for public or private exhibition," and while such handguns are actually on exhibition.
Some have interpreted this as meaning that if you're on the way to the range, or another approved location and decide to stop for coffee or lunch, you're breaking the law. I'm not aware of any cases where this has proven to be true, but I'm also not aware of any cases where it's proven untrue. So basically, it's up to you to pack them up properly and not give the cops a reason to pull you over, should you feel like stopping in between the range and your house.
As far as home storage: If you know, or should have known that a person under the age of sixteen would be able to gain access to any of your guns, you are required to store them in such a way that they are secured against unauthorized use. Once again, the law is incomplete as far as what that exactly means (is a trigger lock enough, or should one invest in a safe?) so if you're sharing the house with teenagers, it's best for you if you lock up your gear. If not, there are no specific storage requirements.
Let's see...other than that, we have a 20-round mag limit, although you can visit to states that allow the sale and possession of hi-cap mags and buy all you want and bring them back to MD with you. If you choose to do so, you may not, under any circumstances, sell, trade, or give away those hi-caps to ANYONE while in-state. If you want to sell/trade/give them away, you must do so outside of MD. Screwy, huh?
There is a one-gun-a-month law, unless you have the Maryland Collector's License, which basically is a simple form that you fill out and file with the state police, that enables you to get around the one-gun-a-month nonsense.
Certain long guns are cash 'n carry (shotguns, most rifles) but if they're on the list of "regulated" arms (AR-15's, AK's, and suchlike) they're subject to the one-gun-a-month rule as well as the 7-day waiting period. Handguns, with the obvious exception of black-powder and C&R firearms are considered "regulated" arms, and are subject to the above-mentioned one-gun-a-month and seven-day waiting period rules.
That should pretty much cover it..
Oh yeah - NFA goodies are A-OK here, provided you follow all the Federal rules. Machineguns are subject to a $10/year registration fee. There are a number of good Class III dealers in the state, if you're into that sort of thing.
Last but not least, welcome to MD - I know it'll be wierd giving up a bunch of the stuff you're used to, but we've still got a fair bit of our freedoms left. Where in MD are you relocating to? I'm in the Columbia/Laurel/Ellicott City area, and would be happy to meet ya at the range someday to put some rounds downrange.