The majority of online casinos want you to deposit money into your accounts as this is how they earn their revenues. Therefor it is in their interests to make sure that they offer a huge variety of deposit options and the processing times for getting the money from your bank account into your casino balance is almost instant.
All major online casinos will offer the usual methods of credit cards, debit cards and e-wallets. A large chunk of them will also allow for bank wire transfers.
You will have to check specifically on a case by case basis whether they cater for specific types of e-wallets such as PayPal, Neteller etc. as it can vary from casino to casino.