And regarding Books I felt comfortable with the following: Institute Material should be the base for all.
Costing: For practice :Reliance compiler on past questions, or Institute compilation,
fast track reading - Padhuka , esp for theory,
and practice OR atleast 3 times from compilation, Padhuka, V.K Kapoor. Steps can be easily understood from Padhuka or you may refer to your class notes.
MICS:
All the books in the market are a synopsis of the Inst Material. So no better resource than Inst Material. Prepare your own short notes or refer to some really useful ones posted on this site for revision. And keep recalling every day. Everyone can understand this subject easily but the test is on how you reproduce the same content and in correct context. So read question carefully and write the same sub headings, points as in the material.
Direct Tax
I followed Girish Ahuja split in 2 volumes making reading easier than a single volume more than 2000 pages! Good presentation and updated suitably with case laws in sequence with provisions. This is for detailed study, along with case law digest of Institute. Students Bare Act by Yogendra Bangar can be used for provision wise reading and revision.
Manoharan is recommended for fast reading and for exam oriented preparation. Do not neglect recent ammendments, case law digest, RTP. Start with that first and keep revising.
Indirect Taxes:
V.S Datey for comprehensive study. Case law digest. Institute material. Suggested Answers.
You can visit dateyvs site for ready referencer.
ALL THE BEST