I recommend
Frederuco's Guide to Root and ROM the TF101 as an excellent, easy-to-follow guide to rooting. (My prior attempts using other instructions were not successful.)
Despite the fact that Frederuco's guide says that the 4.2 builds are "very beta", I am using Android 4.2.2 from Team EOS 4, which is mentioned on Frederuco's guide. Everything seems to be working, including the GPS and MTP file access.
Before rooting:
1. Make sure your apps, calendar, and contacts are backed up through your Google account.
2. Back up as much data as you can using MyBackup Pro. (Before rooting, you cannot save app configuration data, but it will save many of your settings if you are using the stock launcher.) Make sure this is backed up to your external SD card or copied to your PC because the internal memory will be wiped.
3. Use the backup utility of any non-stock launcher (Apex, Go, ADW, etc.) to save its configuration. Again, make sure backup files are saved to the external SD card or copied to your PC.
4. Connect your tablet to your PC and copy any files from the internal memory that you do not want to loose, such as photos (DCIM folder), music, movies, and documents. (I backed up my entire internal memory, but I only restored files after rooting that I knew would not mess things up.)
Good luck!