Simply click on what tickles your fancy and wait for a reply!
A word of advice...
The website Onlinebookclub.org is not friendly to work with. They tell you that once finished with 2 book reviews you can then get paid. A total lie. Also, they treated me like I was completely stupid. They are very unfriendly.
I now work for ReadersFavorite.com who are soooo nice! They stick to their word and have patience with fellow reviewers. They treat we reviewers like gold.
If you can write a summary paragraph and an opinion paragraph, you probably have the job!