How do I LEGALLY sell some software over the net?

Factual Questions
1

Let’s say I write some software and I want to sell it via the internet. Can I just upload a demo to my site, tell people if they want to buy the full version they have to send me a check, and I will then mail the program (or email) it to them.

I’m not breaking any “trade” laws here am I? Do I need to ‘register’ my ‘business’ first? Is there anything else I need to know?

2

You would probably need a vendor’s licence and a federal tax ID number. You can get both from your county government.