Some things you do have to use a credit card for (mainly trial offers, but then you can cancel them). I haven't done anything that required a credit card.
Basically, you log onto the system and you click "cash offers". It will give you a list of the website and the amount you receive credit for. You click the link, enter the info (I use a dummy email account, so I don't get a bunch of spam in my real email). After you complete the item, go back to Treasure Trooper and click the "done" button. You will then see a screen that shows you completed the item. Make sure you play the pearl game (explained below). If you click on "My treasure" you will see the pending and approved items, as well as the amount of pearls and gold coins you have (explained below). You will get paid once a month as long as you have at least $10.00 in approved offers by the end of the month.
Pearl Game: After each offer is completed you can play this game to find the pearl. If you find a pearl (and after your offer is approved) you will see them under "my treasure". After you receive 8 pearls you can by a friendship bracelet from the trading hut (this just means that the next 2 people people that sign up unreferred, you will earn money for -like you referred them). Make sense?
Gold coins: after each offer is approved you receive a gold coin. You can then go to the trading hut and purchase things.
I have not used a credit card for anything and I have still managed to earn a lot. This is a great site. Plus, it has it's own forum, so if you have questions you can post there.
Any more questions, just ask!