I was wondering how exactly payment methods were handeled with a reseller account, when you buy the reseller account does any type of payment method for your customers to use come with it?

After you buy a reseller account, you need to find a billing system that is suitable for your needs. There are many billing systems out there, such as WHMCS (http://www.webhostingtalk.com/whmcs.com), ClientExec (http://www.webhostingtalk.com/clientexec.com), and ModernBill (http://www.webhostingtalk.com/modernbill.com). Personally, I would recommend WHMCS. Anyway, you choose the payment method. If you have a PayPal Business Account, you can accept payments from other PayPal members, along with people who have credit cards (PayPal has a credit card processor).

You can accept orders by a simple form mailer script(also you can integrate a whois script to it if you provide domain registration service) and can track the expiry dates of the accounts by a calender. You can accepts payments via bank transfer and credit cards by Paypal.

Some reseller providers offer a billing script with the reseller account, there are lot of them in the reseller section

It is suggested that you go in for an accounting software. Use WHMCS as it is the easiest to use and integrate. ClientExec can be a pain and ModenBill is a little too expensive for a start.

WHMCS would e fine. It is easy to handle and has got various options. It support most of the payment details.

I was wondering how exactly payment methods were handeled with a reseller account, when you buy the reseller account does any type of payment method for your customers to use come with it?

Usually you need to get a billing script and an internet merchant account to process credit card payment.
There are other options such as PayPal, PayPal pro, 2checkout, worldpay
Some reseller hosting providers offer free billing script.