SC - Manhattan Guide SC before doing that do the Brutal SC first even if u get 20 out of 70 wrong or even 10 correct would work(actually this worked for me a bit at least i now have confidence) search on GMATCLUB, beatthe gmat,urch.com,manhattan.com for the explanation of all the 70 answers
because in these 70 question approximately all the concepts are covered.
try to see the approach you followed and also check the approach others followed normally the manahattan gmat staff.after that I think SC won't be a problem and you will love to solve them
CR - Get Powerscore bible for this try to solve the questions topic wise let me know if you want the details but I have divided question for all the topics for OG11 only and then resolve the OG12 questions or OG10 if you want you can also refer 1000CR
RC - Read ,Read, Read and Read as much as you can from any source Newspapers are the best source but you can also go for Fictional Novels or articles you like to read about just as the starters.
While solving question make notice of few things like which topics you love to read about and which you don't once you have an idea you need to read rigorously about topics which you don't like.......!!!
Even if you know the answer of official question try to find out why in the world you rejected the other 4 options.Selecting a right answer is important but knowing the reason why you rejected other 4 options is equally important.
For Quants: Keep on Giving
Gmat club tests best source....!!!!