Part one of a two-part series. In part two I tackle the issue of how to ask for help online.

You have many options when seeking bioinformatics help online. Here are ten possible places to ask for help, loosely arranged by their usefulness (as perceived by me):

SEQanswers — the most popular online forum devoted to bioinformatics?
Biostars — another very popular forum.
Mailing lists — many useful bioinformatics tools have their own mailing lists where you can ask questions and get help from the developers or from other users, e.g. SAMtools and Bioconductor. Also note that resources such as Ensembl have their own mailing lists for developers.
Google Discussion Groups — as well as having very general discussion groups, e.g. Bioinformatics, there are also groups like Tuxedo Tool Users…the perfect place to ask your TopHat or Cufflinks question.
Stack Overflow — more suited for questions related to programming languages or Unix/Linux.
Google — I'm including this here because I have solved countless bioinformatics problems just by searching Google with an error message.
Reddit — try asking in r/bioinformatics or r/genome.
Twitter — this may be more useful if you have enough followers who know something about bioinformatics, but it is potentially a good place to ask a question, though not a great forum for long questions (or replies). Try using the hashtag #askabioinformatician (this was @sjcockell's idea).
Voat — Voat is like reddit's younger, hipster nephew. However, the bioinformatics 'subverse' is not very active.
Research Gate — you may know it better as 'that site that sends me email every day', but some people use this site to ask questions about science. Surprisingly, they have 15 different categories relating to bioinformatics.
LinkedIn — Another generator of too many emails, but they do have discussion groups for bioinformatics geeks and NGS.

Other suggestions welcome.

Updates

2015-11-02 09.53: Added twitter at the suggestion of Stephen Turner (@nextgenseek).