I'm far from a Mentalist expert but Derren Brown's The Devil's Picturebook has some amazing stuff I'd definitely recommend even if you weren't looking for mentalism.
There are lots of great mentalism books out there, Anything by Phantini is good, Check out psychophysiological though reading by banachek, or PS1+2 also, they're great
umm...Check out any of Kenton's stuff, Miricles of suggestion or mind reading are both really good to start.
Luke J has some cool books, 7 deceptions is nice and I'm a fan of the coral fang too - that has some great routines in!
Hope that helps, the stuff there will give you a good start in the more in depth side of mentalism!