You need a C- and up to get into Adelphi -- but to back such a low grade you definately need some sweet stuff to share with them. Get a good resume written. Not just good, flashy, cunning. Not what you wrote in elementary school -- something on professional grade paper that's been reviewed and looks spectacular with a phenominal heading. It's how you get your scholarships.
Exploit all options, everything you've done, earned, where you've worked, and have favorable referance letters written from teachers and employeers.
Also, with whatever you pick to write for the Admissions essay or whatnot -- do it good. Have a teacher (or better yet, a professor) revise it SEVERAL times. Also on professional paper.
Be creative, zealous, and do whatever it is you have to ... and you'll get in and be given money to boot!