I'm looking for a package for my wifes company to help her automate account management for her web design contracts i.e assign account numbers, gather together multiple orders for the same customer. work out balances and generate yearly reminders for annual costs etc etc.
It probably should run on windows though its not a problem if it doesnt, free would be good if possible but not essential.
I have no experience at all with anything like this so i'm a bit lost. Any advice?
It sounds like you need a simple accounts package. If you look at the lower end of the market, you've got the TAS range (now owned by Sage), whatever the entry-level Sage box is, Sage Instant I think, QuickBooks, Quicken etc. They all come in at around the £99 - £250 bracket.
All of them will record customer details, and associate contracts to the customer. Any of them can do all of the things you mentioned, I think, (most of my experience is a bit further upmarket). I'm also pretty sure all of them have a Windows flavour. If you do find something free though, let us know