We live in WV, just west of Pittsburgh Int. Airport and have driven to Orlando the past two years. My mom lives in NC, so we've always stopped there to spend the night and pick her up (this year she's not going, so we're flying!).
(she lives ~ 30 minutes West of I-77 exit 73, and it usually takes us about 9-10 hours from her house to get to Orlando)
In VA, the Wytheville, VA area has the most hotels....it's roughly 5 to 6 hours from the Pittsburgh area. If you continue on into NC, Mt. Airy, Elkin, and Statesville will be in the 6-7.5 hour window, and are IMHO better places to stop before you get into Charlotte.
If you want to continue on into SC, the Rock Hill area is just south of Charlotte, and is roughly half way between Pittsburgh and Orlando. (somewhere between Rock Hill and Columbia is probably closer to halfway, but there's not a lot there).
Our preferred route is Highway 22 from WV to Highway 18 to Washington, PA; short jaunt on I-70 East to I-79 South; I-79 South to US Highway 19 near Sutton, WV; Highway 19 to I-77 South at Beckley, WV (follow the speed limit on Highway 19....several small towns in WV are notorious speed traps, especially Summersville (but it's a great place to stop for gas and grab a bite to eat)); I-77 South into VA (Wytheville area has cheapest gas usually) then into NC then into SC to I-26 East at Columbia (we usually stop for gas at Blythewood Rd, just before you get to Columbia); I-26 East to I-95 South into GA then into FL; then I-4 to Orlando!
AAA is a great idea.....get one of their TripTiks....they can also help with hotels.
I would also recommend checking out gasbuddy.com and getting their app if you have a smart phone.....we used it to check gas prices along the way.
Hope you have a great trip and have fun planning!