If it's for general office tasks, some web-browsing and listening to music, a Core i3 should do you. If you want to some intensive tasks, then a Core i5.
Anyway, before your answer, i hapen to buy a computer with cor i3 processor
Toshiba intel core i 3, 4GB memory , 640gb hard drive.
i have some genetic and scientific analysis and photo ediiting to do with this stuff. Do you think this will help me