Wow! All of this advice is going to be incredibly helpful. I used to play a lot of poker, and I used the Twoplustwo forums. Anyone new to the site would get a lot of smart@ss remarks whenever they asked questions that may have been answered somewhere else on the site, no matter how buried it may have been. Anyway, I really am thankful for your help.
Your only real path to find consistently find coins worth any money is to search dimes at $250 a box, or half dollars at $500 a box. A silver dime is somewhere around $2.50 while a silver half is around $6 for 40% and $13 for 90%. You can search nickels and find some stuff worth a couple bucks, and can search cents for coins, but if you are looking for what to search for the highest expected value it's dimes and half dollars. To be honest, there are no modern coins which you can realistically roll search for which will bring a premium if you were to sell them. If you like shiny 2011 pennies save them, but you won't be able to go to the local dealer and sell them for a profit. Here is a link to an online price guide, don't take the prices too seriously, which will give you some relative prices.: http://www.numismedia.com/fmv/fmv.shtml
Plus, what's good about halves is that I regularly find a proof, something high grade, or something not intended for circulation. One box in particular had almost two rolls of 2003 halves. I have never found a proof penny, nickel, dime, or quarter through roll searching - and that's through probably $20,000 face.
You'll know a proof when you see it. Modern proofs have cameos and mirrored fields. If it's circulated long enough to have those devices missing, then it's really no longer a proof. However, all Kennedy proofs were produced in San Fran, so look for the S mintmark too. They're better struck coins.
I'm excited myself to search more halves, but my banks never have them - I'll have to order. As for proofs, I pulled a proof 2011 Nickel from a roll today - I was shocked.