And regarding your issue, if you're a rookie you can start learning Excel 2007 and then when you'd be comfortable and somehow fluent you could plan an upgrade to 2010 or 2013 versions. I'd say that 90% of 2007 remains equal in 2010/13 a 5% changes a bit (not radically as between 2003 and 2007) and a 5% is new... but for a starter I think that the 90% it's more than enough. At least today.