Robert, I can't specifically speak for D&D (as I stopped playing shortly after 3.0 came out), but in "coming home" to tabletop games via Roll20's awesome interface, some friends recommended a similar system called Pathfinder. Pathfinder is pretty popular and the core rules are readily available via OGL at the following locations: Paizo Official PRD: <a href="http://paizo.com/pathfinderRPG/prd/" rel="nofollow">http://paizo.com/pathfinderRPG/prd/</a> Paizo + 3rd Party SRD: <a href="http://www.d20pfsrd.com/home" rel="nofollow">http://www.d20pfsrd.com/home</a> There are tons of different character sheets available, most are really personal preference and there is a significant difference between how you plan to use them in conjunction with Roll20, but the next major update due at the end of the month of May will have some awesome community created sheets that will make it so much easier to begin on Roll20. Hopefully this was helpful in some fashion, good luck!