I think a lot of people don't really understand what Moab is, especially people coming from areas where the only wheelin' available is in private offroad parks.
Technically speaking, Moab is just a town in southeastern Utah. All the wheelin' is done in publicly owned BLM land surrounding, or at least 90% of it. There is some wheelin' on National Park land and there is the privately owned Area BFE. Some of the trails are within 10-15min of the town of Moab and some of them are as far away as 30min or more - it kinda depends on what you want to call the "Moab area". Here is a list of the more common trails:
1. Behind The Rocks
2. Chicken Corners
3. Cliff Hanger (aka Amasa Back)
4. Copper Ridge
5. Crystal Geyser
6. Secret Spire
7. Dolores Triangle
8. Dome Plateau
9. Fins and Things
10. Flat Iron Mesa
11. Gold Bar Rim (including Long canyon and Gemini Bridges)
12. Golden Spike
13. Hell Roaring Rim
14. Hell’s Revenge
15. Hey Joe Canyon
16. Hotel Rock
17. Kane Creek Canyon
18. Lockhart Basin
19. Metal Masher
20. Moab Rim
21. Poison Spider Mesa
22. Porcupine Rim
23. Pritchett Canyon
24. Rose Garden Hill
25. Secret Spire
26. Seven Mile Rim
27. Steel Bender
28. Strike Ravine
29. Top of the World
30. Wipe Out Hill
31. 3-D
Each of those trails is rated on a scale of 1 to 10 (used to be 1 to 4++). So you can do stuff that is a "1" (or easy trail) or the hardest stuff rated "10". The easy trails can be done with a factory truck.
If you travel to Moab on your own you can run virtually any trail just by driving to the trail, locking in the hubs, and going. A couple of the trails - Hell's Revenge for example - do have an entry fee of about $5 IIRC but no other restrictions. You can run the trails any day of the year and any time of day.
The advantage to going with Blazer Bash is that you get to experience some of the more popular trails with people that know the area. Plus you are sharing the trails with people that understand how to navigate the obstacles with a fullsize truck. Not to mention getting to check out some of the ideas and concepts other guys have come up with for their trucks AND you can see how well they actually work on the trail. And as it's already been addressed, if something happens to you on the trail, everyone always pitches in to help you get back to town. I know there's a good story about last year's Pritchett Canyon run. The really cool thing is that the Watson's from ORD carry just about everything you could ever need to fix a rig - including an onboard welder - and they never hesitate to help out.
In '05 I had the misfortune of breaking my rear axle at the beginning of the second day. I was able to get the truck fixed in Moab so we could drive it home, but not before Blazer Bash was finished. We didn't have any trouble finding a ride for myself, wife, and 3yr-old son on the final trail of the event.
We try to offer trails that will suit the needs of everyone. It's hard to do because for one thing what's easy and what's hard is all subjective. Some of the stuff advertised as "hard" isn't really all that. Then when you think you're on the "easy" road, things turn out a bit more complicated than you expected. But that's why it's nice to have the experienced guys along with you on the trail. Either way, we can pretty much guarantee everyone will have fun.