Authors come in two categories in this department.
Those that want anyone that they can find to read their novel. And those that look for their target audience. I recommend that authors do the latter.
Betas also come in the same two categories.
It’s more beneficial to find betas that are genre specific. People that read (and love) your genre will give you a good taste of your target audience. Someone that reads exclusively westerns, for example, probably wouldn’t have amazing advice for that alien technology in your sci-fi/thriller. Not to mention, it’s good to show it to people who may want to buy it when it’s finished 🙂
Betas should advertise their favorite genres; authors like to know what kind of reader you are and what you read most.
You also should let writers know what guidelines to follow when submitting their work to you. And any other tidbits about your services.
Do you require a blurb, to see if your interested? Maybe the first chapter? Do you have a limit on how many pages/chapters they should submit at a time? What genre is it? How long is the manuscript?
It’s important to let them know when you’ll be getting your feedback to them. Let them know the best way to contact you. Do you like to give your impressions first and then ask them if they have questions? Do you require a question sheet with each chapter? Or whole book?
On my blog homepage, I keep a submission button and when I’m looking for authors — I post these all over the place on the web. When the emails start pouring in, and they do, I look at blurbs to help me decide if I want to read their manuscript. If I’m still not sure, I ask for a few chapters and take it from there.
If you lose interest during a read through of your author’s novel, let them know. Don’t just ignore them and hope it will go away. It’s important to let them know what happened and why you feel that way. That’s feedback too.
Making clear submission guidelines, not only is very professional, but it also let’s your author know exactly what you expect out of the relationship. They can decide if they want to contact you. Are you their target audience? Is your submission pace going to work with any deadlines they may have? Things like that can be answered before they even submit with guidelines.
Guidelines are a way to let the author know if your services are right for them. I believe that every beta reader’s preferences serve a niche, so if some pass you up… trust me, there will be plenty that will want to work with you.