Depending on where you live, picking an online poker site to play at may be easy or very difficult. For someone living in Europe, the biggest challenge is narrowing down the choices. There are so many sites out there, figuring out which one to play at could take a lot of research or a really big dart board. For someone in the US, the biggest challenge is finding one that not only will accept US players but, makes it reasonably easy to deposit funds and withdraw money later.
The first step is to look at the sites FAQ. Almost all have a specific answer about whether they accept US players. The next thing to look at is how they accept deposits and process withdrawals. The US banks are compelled by law not to allow individuals to transfer money to or from online casinos. The same holds true for major credit cards. For most people, these are the main ways they move money. The other big electronic method is PayPal. While there are a lot of sites that accept PayPal, the PayPal terms of service state they will cancel any US account that moves money between PayPal and an online casino. PayPal means it and there are plenty of people who have found out the hard way.
Some will accept deposit by personal check or money order. This method takes quite a bit of time since you have to wait for the mail to deliver it and then the company has to process it and let you know everything is ready. Most players are depositing money with prepaid Visa and MasterCards. These can be found at many convenience stores and money transfer and check cashing locations.
Almost all sites are willing to mail a check when you decide to withdraw money. How much red tape is involved varies from site to site. Check the FAQ for this information as well. It is also a good idea to check various online poker forums to find out just how easy the process was and how long it took from people who have already been through it.