www.coursera.org - Bioinformatics is developing very rapidly. With new tools and software it is, now a days, easy to analyse the large scale genomics datasets. But we need to understand the background of software/tool to better explain the data...
samtools.sourceforge.net - In current genome era, our day to day work is to handle the huge geneome sequences, expression data, several other datasets. This link provide a comprehensive list of commonly used sofware/tools.
bioinformaticsonline.com - In our computational biology work, we mostly play with DNA or AA string. For string based programming work this regular expression cheat sheet is really helpful. Keep it handy.