Here are some links to help answer your muzzle-loading questions.
If you have a favorite of your own please post it for the rest of us.
Mostly Traditional links http://www.coon-n-crockett.org/linklist.htm
Toby Bridges site http://www.hpmuzzleloading.com/
Gun related manufacturers http://www.guns4u.net/manufacturers.htm
Ballistic calculator http://biggameinfo.com/BalCalc.aspx
P+R bullets http://www.prbullet.com/
Downloadable targets http://www.targetz.com/targets01.htm