I actually bothered to email HMRC rather than believe the silly conclusions by news articles and you apparently pay capital gains tax on them, there are no other rules regarding Bitcoin in that area so you can easily trade over the internet with Bitcoin if you want to. So if I bought a new computer from Bitcoinstore for example with just Bitcoins the UK and German government as well wouldn't give a crap about that, but if I sold them past the £9,000 or so tax threshold I'd have to pay tax on it.
The only difficult thing is checking out how much you need to pay for that year based on what you earn when you sell.
Places like localbitcoins will now give you a log of transactions, that will help you with tax massively. If you are a trader anyway. Shows what you bought for, then sold for. Of course if you buy other ways, like meet strangers and buy in cash they cant prove anything and have to take your word but tax evasion is a serious crime.