Is there a good resource section on here, maybe just follow in someone elses exact footsteps regarding distance and motels etc?
Get the AC maps, and check out the addenda on-line. They offer a great resource for planning, including exactly the motel and distance information you're looking for.
Many (most?) of us who've ridden it either carried some camping equipment, or had a support vehicle which could carry it. We met a couple on the Northern Tier who'd planned their entire trip based on AC maps, with motel reservations for each and every night. That's not a bad idea, especially in July and August in the west, as motels are few, far between, and often booked solid on weekends and in popular tourist locations.
There's a couple of spots on the TransAm I'd try to book really early, cross my fingers, and hope. The first is the Grand Tetons and Yellowstone. Book spots early in January, as they fill up fast. The second is the stretch through Jeffrey City; there's no lodging between Rawlins and Lander, if the reports of the Jeffrey City motel closing are true, and it's about 120 miles. If you hit a bad headwind, like we did, you're going to be hurting. I'd recommend you plan on two nights either side of that stretch to rest up before and after that ride.