MS Excel is probably top of the pops when it comes to the most used and most asked about software application. Most people have a love/hate relationship with it as it drives them mad when they can’t seem to get it to work or it does something ‘weird’ but when it does work they fall back head over heels in love again.
There are many brilliant resource sites I have used over the years and I’ve listed a couple of my favourites here (disclaimer: they are third party sites so visiting them and using the information contained therein is at your own risk of course and the links will open in a new tab on your browser).
Vertex42 – Been around for years, really good resource
Digital.com – A collection of lots of really good information, not just on Excel but loads of other stuff too!