first thing (if you want accuracy and don't care how it looks)..it to take off the barrel band..that will free float the barrel and instantly improve accuracy.
Best mod you can do is a simple hammer (volquartsen or power custom or skeeter..all are good) and a buffer to keep your scope from moving (and reducing noise) and forget all the other expensive stuff unless you really want to make it look hot, or you want to start shooting competition.
WHAT? A 10/22 parts store owner telling you to NOT buy everything under the sun? yep...thats how I roll.
Check out
Ruger22.com my "help" site. (there is an old site and new site link as it is still under construction. the best stuff is still on the old site)
It has over 100 detailed photos showing how to do anything to a 10/22 and how to install any mod part.
If you need any help, ask...there are some top notch 10/22 smiths hanging around here.
Bob