Tax on distributing DVDS on line

[advice needed]

Hello all, I work full time and pay tax and N.I and I am planning on selling a DVD on line and have a .com domain and a uk server (i think). I need to know what tax(s) if any I am liable to pay? and I am considering setting up as a sole trader and need advice regarding what I actually need to set up, i.e insurance, tax, n.i, profit related (class 2) (class 4) etc
Any help is greatly appreciated.

[JGOffshore]

Have a look here as a starting point (http://link4business.info/category/starting-a-business/). You will need to search around as there is a lot of the information you need but not side by side.