Reproduced from Coffee Time Romance with Amy's Permission.
A "beta reader" is someone who reads your book cover-to-cover the way a normal reader would, and gives you feedback from the perspective of the reader's experience.
The difference between a beta reader and a critique partner is basically:A beta reader reads your ENTIRE manuscript--and usually only reads it once. Your goal is to have fresh eyes that have never read any parts of it before. You're looking for how the story hangs together and works for a real reader.
A critique partner usually only reads a few chapters at a time and is usually (but not always) another writer. So they are more inclined to give you more indepth, writer advice versus "this just didn't work for me and I don't know why" which is what you would get from a beta reader.
A critique partner may also read the same chapters several times.Most critique partners will not read the entire manuscript end-to-end, so they may not be able to give you the view of how the whole thing hangs together.I'm sort of in the same boat you are.
I've had critique partners for many, many years and they helped tremendously--at first. But they have moved on, and I find myself wanting more of a beta reader (which is what authors like Jenny Crusie use) to read the whole book and tell me how it hangs together, rather than individual chapters.
It is very, very difficult to get a beta reader because of the committment to read the entire book. You can get critique partners much more easily, but there is a trade-off in that you're only going to be working a few chapters at a time, and you have to critique their work, too, so you will put time into their work.
If you try to find a critique partner, you need to find someone you are sympatico with. You don't want someone who will say, "oh, this is great" when it isn't, or who will blast you to the point where you give up. It's hard, either way. There are a lot of online writers groups, however. Many are affiliated with RWA and require RWA membership, but that is a good resource.
Hope this helps a little!