for self study, the following text-books and materials have been tried and trusted :
1. Air Regulations : Air Regs by Wing Cmdr. Bali , a/c Act 1937 from the DGCA website
2. Meteorology : Meteorology by Grp.Cpt. I C Joshi, GSPs,
3. Navigation/Radio Aids : GSP, notes of wing.cmdr(rtd)S.K.Buti, Seth or capt. Surinder's. (Especially for problems on PET, PNR)