My background is computerised systems however i did use a manual system for a while and would recommend moving to computerised.

I have used MS Accounting and TAS books but mostly Sage. I have found they are much the same really, it just takes a little bit of playing around with them to understand how they work and with you're bookkeeping background you should be up and running in no time.

As to which package you should chose, i use Sage Line 50 however it is expensive, Sage Instant Accounting is the entry package if that suits you're needs. Sage has got a CIS add-on however the accounts package itself can deal with CIS without the add-on - i have used it for this purpose and it worked well, a bit fiddly too start off with but once you get you're head around it, quite simple.

Some people, as you may find from any other replies, really dont like Sage but i use it regularly without any problems, and if any do come up, this and other forums do help. A computerised bookkeeping course could help in getting you up and running - i did one and it was indespensible.

MS Accounting is free of charge, some do find it rather slow in operation but you may put up with it because its free.

The type of package you choose is not easy, i chose Sage because most of the people i work with use Sage so it was a no-brainer for me but good luck and you'll be glad you switched.