The sites twofish has recommended are excellent, but also a note to beware that arxiv contains all sorts of wacky articles, so if you're using them for a research project you might want to search through appropriate journals.
Otherwise, without having an understanding of specific areas you might find it difficult to use those sites. If there's a research group at your university that cover the area you're interested in I would approach one of the members; convey your interest and ask if they can recommend some introductary reading.