Bookkeeping Start Up

If you cannot use online/cloud software applications (they are very reasonable) go for the latest desktop version of QB. If the client is small and does not have accounting software then with QB you can upload the client bank statements into their your QB and then all you have to do is allocate the bank transactions.
So the beauty of the uploading the bank statements into QB is that the books are balanced from the start, you just have to allocate expenses & deposits.

You should also look at getting a neat.com receipt scanner. Typically a lot of small businesses just put receipts into a box and hand them off to their Book Keeper for their year end tax prep.
A neat scanner will have you 80% of the time to manually sort the receipts and will make you look very professional. Moreover the neat scanner produces an Excel file which you can use the find function to locate bank transactions from QB Bank up load. So if you have a irregular bank transaction say for $1267.98 you can use an excel find function and quickly locate the actual receipt.