The ultimate roads in Ohio are down in the southeast (Appalachian Hills region) corner near Woodsfield, Caldwell, Lowell, and Marietta, with a second place to the Hocking Hills State Forest and Lake Hope - Zaleski state forest areas. A bit far for you in Marion, but the roads WILL NOT dissappoint!
You should really try to get a cabin, campsite, or hotel around Hocking, Nelsonville, Athens, Burr Oak. Ride 2 days. Ask me for details. The Hocking State Forest primitive campsites are my favorite campground sites around, spaced out & private. Ask me for camping/lodging details & route recommendations for these areas.
One of the best roads to start your journey deep southeast on, OH-78 Scenic Byway, is amazing from just out of Nelsonville all the way to OH-555, "The Rim of the World" section high up on the ridge 400' above Burr Oak Lake - check out the views as you get to clearings closer to 555. "The Barn" next to an abandoned 1950's white Aluminum siding abandoned 1 story house boasts views that make you feel like you're on the Blue Ridge Parkway, a must-stop-and-stare unofficial scenic overlook down the road from the official overlook.
555 is super technical but not terribly flowing. 78 is good all the way to Caldwell but a little boring near McConnelsville. You can take it to OH260S to OH26 "The Covered Bridge Scenic ByWay" to Marietta and then 676 (great on the ends boring in the middle) toward 555, then link up to 377 back to 78. Great great ride, easier navigation than my personal ultimate twisties routes, plus excellent fun and scenery for most skill levels.
Around 26&260 and southeast from the hills toward the Ohio River are some more GREAT routes (255 is best, 260 again, Archers Fork Rd, Rinard Mills Rd, 800 (faster/easier curves), 556, Sykes Ridge Rd, & the very twisty oh-536 that will be 1 of the best road in ohio with the scheduled 2017 new pavement job. rough now and contains a couple of turns that will wreck you, especially the one after the stop sign at Sykes Ridge Road southbound, 1 mile or less down, 15mph max decreasing radius blind curve with elevation drop off sends MANY riders across the other lane and into the field. Not a beginner road! Bunch of mid speed curves with some occasional very tight ones thrown in to catch you off guard & ruin your day - USE CAUTION!
The Lake Hope/Zaleski area is great fun with nothing terribly technical but loads of good mid speed curves and hills. 278 straight outta Nelsonville, 328 (south of 56 is best), 356/691, all connected by 56 in the middle & 50 on the SW end. Two Mile Rd is another good one off 278&56.
Hocking Hills has some amazing routes on 374/664/56/BIG PINE RD btwn 374&664/Thompson Rd-Thompson Ridge Rd aka "The Little Blue Ridge" etc. I have a bunch of other awesome twisty county roads north of there (and a few on southern end of Hocking) around clear creek Rd area that I zip in & out of, some pretty darn technical, many chipsealed. This area is best hit on weekdays or off-season due to all the traffic generated by the hiking & cliff/waterfall sightseeing traffic, truly the most amazing natural region in Ohio. I hike here often and ride this ARE frequently - the good county roads start just 40 minutes south of my back door.
I ride all this stuff & West Virginia (Monongahela area especially - BIG MOUNTAINS!) as frequently as I can get out.
Drop me a line in the riding season if you ever feel like riding some great twisties in the Eastern/Southeastern Ohio hills, I love that area & riding the twisties.
I've been scouting some more roads out past Newark/Coshocton/Zanesville, found 2 of the best roads in the state just north of Cambridge, NOT AT ALL beginners roads tho.