As developers we don't have all that many business expenses. Maybe you'll do better than me, but I don't think I made huge tax savings. As a director I have to do the personal tax paperwork on top of my company tax returns. There are more regulations, deadlines, and submissions for a company than an individual.
For my first year trading I signed up with an accountant (I was painfully aware that I didn't have time to learn the tax stuff and worried about making a mistake). If you have the time and inclination, and use a good accounting program, I'd recommend learning to do it yourself asap rather than hiring one.
If you go the sole trader route, I recommend opening a new current account and using it for all and only your business transactions, like it was a company credit card. That will make doing your expenses a lot easier.