E-gold is one of the oldest internet payment system. The idea behind it is brilliant, nothing comes out, nothing goes in, it's just virtual money covered by real gold. They have an amount of gold( which may change depending on their investitions and strategies) but from the user's point of view you virtually have just some part of that gold and you can send it to other users and get goods or services in exchange. Some users are exchangers and they give you real money for the e-gold.
So, if you need to buy something with e-gold and you signup for e-gold but your account is of course with 0 balance, what you do? Simply you must find an exchanger. You give him money or kind of emoney such as: webmoney, paypal, epassporte, moneybookers, stormpay. The most important thing for you is to research if the exchanger is really trusted and not a scammer. With virtual money and specially with those non-refundable such as e-gold, scamming is not uncommon.
How to get e-gold with a credit card? very easy. Although most exchangers don't accept CC payments due to high fraud rate, if you have a credit card, it means you have a bank account so you can make a bank tranfer. With bank transfer you are much more trusted so you will get your e-gold if the exchanger is also trusted. I recommend one exchanger which I tested and succeeded: klad.ee. There you can do wire <-> egold <-> WMZ <-> etc.