Clustal X http://www.clustal.org/
Mega http://www.megasoftware.net/
NCBI (pubmed, sequence searches, BLAST): http://www.ncbi.nlm.nih.gov/
Various DNA software: http://www.justbio.com/
Biology Workbench: http://workbench.sdsc.edu/
Genedoc (publication-quality sequence alignments):http://www.nrbsc.org/gfx/genedoc/index.html
Gene Runner (free DNA program): http://www.generunner.net
Links to phylogeny programs: http://evolution.genetics.washington.edu/phylip/software.html
Expasy protein tools: http://us.expasy.org/
Gene Fisher (degenerate primer design): http://bibiserv.techfak.uni-bielefeld.de/genefisher2/
Prediction Servers: http://www.cbs.dtu.dk/services/
For protein secondary predictions: http://bioweb.pasteur.fr/cgi-bin/seqanal/toppred.pl
For protein domains: http://smart.embl-heidelberg.de/
BCM Search Engine: http://searchlauncher.bcm.tmc.edu/
Scientific search engine: http://www.scirus.com