These
free books will keep you busy for quite a while, (Also, all of them have been recently updated):
Instrument Flying Handbook (2007):
http://www.faa.gov/library/manuals/a...ying_handbook/
Instrument Prcedures Handbook (2007):
http://www.faa.gov/library/manuals/a...ures_handbook/
(Look at the bottom and click Download complete IPH)
Aviation Weather Services (2007, Brand spankin new):
http://www.asa2fly.com/Aviation-Weat..._product1.aspx
(Look on the right and download the whole book)
Oh, also there is a good amount of info in the AIM:
http://www.faa.gov/airports_airtraff...ns/ATpubs/AIM/
And regs (Specifically Part 91 Subpart B):
http://www.risingup.com/fars/info/91-index.shtml
Have fun.