hi
when you recieve payment you will usually see a name - so hopefully you will be able to work out from your work list who it is that pays fairly easily, some wil pay on completion if they are home, but if you ask then to use house number and road name as a reference when they pay that will help too.
also we use window cleaner pro - others like george, both are simple computer based programs so you can input customers addys and details when the cleans are due and each day you just print off what needs doing, it also has a debt list, so you can see who owes what - WCP is very easy to use, and others say the same about George too.
WCP also allows you to input all your expense etc, so your books are almost "ready" at the flick of a button hope this helps
Also you may not need to open a business account - check out what fees are there, you may do just as well with a basic bank account with no charges, all will do what you need the coop do a good basic account - fully internet based, so people can make payments online, you can log in and see whats arrived and you can bank cheques or pay in cash at any post office with that account too.