Good suggestions so far. I'm in a similar situation as the OP - my rifle skills have lagged behind my handgun skills, so I've been working on them a bit. Obviously, I'm no expert, but in case it gives you some ideas, here's what I've been doing:
1. Equipment: Make sure the rifle is up to the task. I figure my rifle (a CZ550) doesn't have to be über expensive for what I need, but it does have to be up to snuff. That means screws that are consistently tightened down, and ammo it likes. The scope has to track well, and have a consistent zero, and it ought to have a good trigger. A good bedding job wouldn't hurt, either. I sprung for a decent leather military sling, too.
2. Rather than staying glued to the bench, I'm working on my field positions, including seated, kneeling, prone (using the sling) and standing.
3. I'm trying to get a feel for the bullet's ballistics, so I can do all the above while varying distance.
4. I shoot my .22LR (also a CZ) a LOT when practicing the above.
5. I dry fire at home from field positions to practice trigger control & bolt technique.
6. I also have a decent (but also not über expensive) air rifle, so I can live fire in my backyard when I want something beyond dry fire.
7. I'm planning (haven't had the chance to do it yet) on using my .22 in CMP Rimfire Sporter matches in the area. Whatever .22 you've got, it's likely got a home in RS, and it's shot standing, seated and prone - the same positions I've been working on. As mentioned, an Appleseed event seems like a very good idea.
8. Here's a rifle technique blog I think is very helpful:
http://artoftherifle.blogspot.com/