As you'd expect, every country is different. Noonsite is probably one of the better sources I've come across.
www.noonsite.com/

simmrr said..
Having never gone outside Oz, whats the procedure for entering different countries by boat?

Permission at a consular before you go or just head there and get one on entry?

And what if you plan to stay and work a bit? Any examples appreciated.

A few different issues involved with entry to foreign ports.
The boat must be appropriately registered and documented and crew passports in order. Then there are the customs and immigration clearance procedures from country of departure to be followed. These are all quite formal procedures requiring contact in a timely fashion generally with Border Security. All departures and entries must be from a Port of Entry.
Again formal procedures and notification required for entry to foreign ports, typically 96 hours advance Notice of Arrival documents. On arrival at the customs quarantine berth a formal quarantine procedure, customs and bio security procedure and immigration procedure must be followed.
in all cases the appropriate immigration ie visa requirements etc will be followed as per any mode of entry to that country for nationality of passport holder.

LooseChange said..
en.wikipedia.org/wiki/Visa_requirements_for_Australian_citizens

Most countries allow you to rock up at the front door of an official port of entry and do your check in, Harbour Master, Immigration and Customs. Some you have to pay a fee and some you have to pay a bit more than a fee, lo and behold some are free and have honest officials. Some countries you don't even need a visa for.

Most Visa on Entry countries do not allow you to engage in any kind of commercial activity as you are there on a tourist visa, plus some only grant 30 days stay while others automatically give you 90 days, although in most cases you can extend.

I think that the more correct statement would be that no country simply allows you to rock up at an official port of entry and do your check in unless ALL notification, documentation and visa requirements are in order.