In my own experience, you can start doing sketches and using your PayPal account attached to your bank account. But some people started to use AlertPay because have more freedom than PP and is available worldwide (Paypal maintains restrictions in some countries and don't allow to pay or receive money in another places)

What's the difference we don't allow to pay our money to people from around the world?

I mean PP.

PayPal allows to you to receive and send money worldwide because you live in United States. I have restrictions in my PayPal account because I live in a Latin American country (I can't receive money, only send it). So, I started to use AlertPay, that offers the similar service than PayPal but much better. AlertPay also allows me to do transactions and receive money worldwide.

I forget how I signed up for pay pal, but as for starting commissions, that's not hard, you just need to type up a journal stating that you are accepting commissions.

I'd recommend saying you have something like ___ many spots availible. For example, say, in your journal that you're availible for commissions and you have ten slots open, and then when people respond, put their name in one of those slots. You can say that any one after the tenth person who responds will be put on a waiting list. The number of slots you have availible is dependent on how many you think you want to do. If you're just starting out, I'd keep it a small number, so you know you can handle it.

Also, pre determine how much you want to charge. Since you're just starting out, I would low ball it, until you aquire a good reputation. Just be sure you deliver what you say you will.

For instance you can write in your journal, that you are offering one full-body charater commissions. (this keeps people from asking you for something like ten charcters playing cards in a swimming pool, or something clearly outrageous like that) Black and white only 2 bucks, and full color five bucks. Background can be charged extra. Just be really clear on what your offering and how much payment you expect, otherwise you run into trouble.

You have to decide the amount.

Also, you might want to mention about how long your commissioners can expect to wait.

Make sure they understand that you're only doing digital commissions, and that you're not planning on sending out hard copy originals. Maybe offer a high resolution file so they can print one out on their copier.

You will also want to make sure (if you do use pay pal) that you mention that everyone who commissions you must have pay pal; otherwise you can say you will accept money orders via snail mail.

Here's an example of how you might word your journal.

Hi, all, I am offering commissions.
There are two kinds availible. Simple black and white one full-body character, no background commissions are five bucks. Full color one character commissions , no background are ten dollars.

Backgrounds are extra (since they take more time) please say what you'd like in the background, such as trees, a beach, etc. Simple background will be an extra two dollars, more complex ones will be five dollars.

These are digital commissions. I will keep the original, and I will email you a high resolution file for you to print.
I have FIVE slots open, so please post your name, character references and any other applicable information.
I can only accept paypal (sorry)

Commission work can really be a nightmare if you get cranky demanding customers. Some folks are clearly the sort who can't be pleased, which is why it's important to say what you are willing to do and for how much money. So commuincation is super important. Write your specs, and re-read and re-read it again before you post it.

Also you can read other people's commission announcements for hints on how to write up your own.

Its not that hard. You set prices for what you will work on and inform everyone what you won't work on. Post this information with how to find your paypal account and make sure you get what they want and you to do and the amount before you work on it and the rest you should know.