I went sole trader initially, until it become much more cost effective to go limited.
As mentioned above there's a trigger point in earnings where it becomes more worthwhile to be limited. Accountants fees are bit higher looking after a limited company compared to a sole trader as there's a bit more to do in terms of admin, but it's still worth it once you hit that trigger. Bring in the missus as a shareholder to top up her salary, there's loads you can do when you reach that point.
Depending on what you are doing and what risk there is speak to an insurance broker and get some good liability insurance (not expensive in scheme of things) and a decent accountant you can trust, given time he will save you money and time. If you open a business bank account you'll get free banking for 12 to 18 months as well. Good to keep it separate from your private/personal account (just for record keeping ime)
Do you have any friends or family who run their own business - you may get recommendations on accountants and the like locally. I'm a dubious sod and I don't like putting my trust in someone I don't know.
And some software to track expenses, purchases, sales, profit etc - small steps and all that.
Good luck