Please suggest how i can prepare for BMS entrance 2013(DU),from where can i get sample papers for practice(any links on d internet).?

I want to know if its important to join a coaching institute and which all r good for the purpose in case i do.i have only 18 days left.i cant find any study material or sample papers on the internet, please help.please provide tips for preparation and links on the internet wich can be of help.