There are no third party books available on LoadRunner, however the manuals are quite good.
Why no authors? THis is a direct side effect of some stringent licensing provisions which prevent publishing without permission from HP directly due to the copyrighted nature of the API set and GUI. And yes, both Mercury and HP have enforced that copyright.
I'm learning LR as well (came from SilkPerformer of 8 years) and found LR's application help facility to be very good as a reference. Pretty much every screen is described in horrific detail.
If you are looking for a way to apply LR to your project, much of this will come with experience. Also bear in mind that the protocols will have a very strong influence on how you proceed. In other words, someone saying they "know Load Runner" is kind of vague due to the protocols and specific approaches for each. This site is pretty good if you get stuck (hint: use the search feature first).