Hi Nicola,
If you're looking for bookkeeping or accounting option, FreeAgent is a pretty great software option - they're based in the UK (in Edinburgh actually - I note you're in Scotland). Depending on who you bank with you can set up your bank information to go straight into the software. You can even file your tax returns directly to HMRC using it. They do a free trial and have really great support if you want to check them out. I know there are a number of salons in the UK who use it.
Another thing that might help you keep track of your sales etc is a salon management software if you don't already have one. There are lots of options out there that suit different salon needs. If you're looking for something quite simple that does key things like online booking, point of sale and reporting without costing the earth, you could try baxus. Again it has a free trial and it's based online so you can use it anywhere.