There are actually quite a few ways to find the best online bingo sites but perhaps the very best way is to read customer reviews. Most sites will let you go in and browse around a bit before you are required to make a deposit to play. Although you may not be able to actually go into any of the actual game rooms and play, unless they give you a no deposit bonus, you will at least get to read the rules of the site, read the FAQs and look for customer reviews they may have posted. If you stumbled upon that site by chance after searching for online bingo, perhaps there are reviews on the site that directed you there. You can also find sites that rank online bingo sites and have reviews written so that you can learn a little about the site before you even go there.
However, one of the best ways to find an online bingo site is to talk to friends online. You probably already play bingo at one of the free bingo sites. Many of those people have tried, or still play at, pay-for-play sites. Ask them which bingo sites they like best. You will be surprised at the number of online friends you have been playing with will be able to tell you the best online bingo sites to try. Once you find a good online bingo site you will probably see many of the people you have chatted with in the free game rooms.