Apologies, Richard, but I have a few more questions to make sure I'm clear on everything:

Step 1. I don't need to register a company, which would be done through AHV. Instead, I simply register myself as a selbständig/Einzelfirma (Sole Trader), which is cheap, if not free. Where will I find the application form for this? Is this also done through AHV?

Step 2. Note to self; when registering myself as a sole trader I will need to find a name for my business that includes my surname. Further; my website domain can't have the same name as my business.

Step 3. I set up a bank account in the same name as my business. Once I'm registered and have a bank account in place I can start work immediately.

Step 4. To ensure I make all the correct contributions I then need to register with the AHV, whilst taking advantage of such organisations as the SVA. Is registering with AHV regarding contributions also free?

Step 5. [Originally posted by Richard] "You may also find it useful to invest the SFr. 150 - 200 to register your business on the trade register." Does this apply to me and would this be done through Handelsregisteramt Kanton Zürich?

Step 6. Regarding a residency permit [Originally posted by swissbob]: "Go to the local residence office (town hall, Kreisburo, Gemeinde) and state your intent to be self employed. You are eligible for a special 6 month B permit after which you have to prove you are viable, then you will get the 5 year B." Should I do this straight away or is it better to wait toward the end of my 90 day tourist visa?

Phew... I think that's it.

Sincerest thanks for your help!
Chris