It's probably good to start with something like Eckhart Tolle's work, which is fairly simple and doesn't have any specific religious baggage; the simpler the teaching, the better. You could have a look at
this Eckhart Tolle video to get you started.
There is of course lots of valuable wisdom to be found in various traditions/religions, but then it's probably best to sample different teachings to avoid getting stuck in the particulars of each one.
Some more teachers for you to look up: Carlos Castaneda, Ram Dass, Gangaji, J. Krishnamurti and Byron Katie.
(edit: and if Eckhart Tolle et al. are too new-agey for you, I agree with impaul99 about looking for ones with a 'practical application' first)