To avoid further confusions:
The total amount of coin domination will be 10BTC, not each coin. For example either 1000 0.01 Coins or 100 0.1 BTC coins.
PM BitcoinAccepted for the payment address.
Luckily I don't live in the UK
You have to do a tax return in your country. You can obviously declare as much as you wish and in some countries you have tax allowances so you can trade a certain amount before you start paying tax. For such a small business I wouldn't really worry about it. From what I have worked out the earnings I will make from this will be half of what the tax free allowance is per year. That is of course unless you start generating an extremely high volume of sales. I would then seek the services of an accountant to calculate and submit your taxes. Accountants generally do all this for you and can even arrange tax payments too.