Tools you need for analyzing DNA and protein sequences:

EMBL (EBI)
www.ebi.ac.uk/translate/

ExPASy Molecular Biology Server: There is an entire proteomics section where you can translate, reverse translate, or any number of other things.
www.expasy.ch/tools/

NCBI (National Center for Biotechnology Information):  Main purposes for this (for this class) is to use the BLAST search engine, looking for DNA, RNA, or protein sequence homology with known sequences.
www.ncbi.nlm.nih.gov/