For several years now I’ve been a huge fan of Microsoft Excel and Visual Basic for Applications. I’ve learned so much yet there is still so much to learn!!
There are some fantastic Excel sources around ..but I’m pleased to say one of the best is run in my home state of Western Australia http://www.ozgrid.com/.
There are also great Excel groups on www.linkedin.com as well as blogs such as: John Walkenbachs – spreadsheet page and http://www.contextures.com.