I prefer the RV Repair and Maintenance Manual by Bob Livingston
linkBut if you need help with the chassis/drive-train/etc, get a manual for that.
2008 F350SD V10 with an 2012 Arctic Fox 29-5E
When someone tells you to buy the same rig they own, listen, they might be right. When they tell you to buy a different rig then they own, really pay attention, they probably know something you don't.