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Any provider with PHP and mySQL will be able to run your site. Many web hosts are starting to provide this basic functionality. Be on the lookout for how many SQL databases they provide and other such features. Comparison shop everything you look at. Try to avoid resellers and go to companies that offer stability and support.
You may find it hard for webhosts to provide support for Xoops, they will just send you here. What they will help you with is setting up your SQL database and how to run it's features.
Take your time and don't rush into it. Moving after you have a host can be troublesome to say the least.
Watch out for package deals. Just because it says 7.95 a month, doesn't mean it will actually cost you that. You'll get that price if you pay for 2 years hosting. Before you sign up, you want to be sure you are happy with your host. Make sure they offer a guarantee of some sort.
For beginners, I recommend
http://www.GoDaddy.com or any other such large company that can cater to your needs. (I use a different host) We're all new at this at one point in our lives and if there is anything you need to know, feel free to ask here on the forums.
There are no stupid questions, so don't be afraid to ask. I havn't covered all the bases here so others are welcome to chime in at any time.
Cheers