There are many different factors to consider in choosing your psychiatry residency program. I'm not aware of any books that outline all of the nuances of residency programs. However, the website that stands out most in my memory (I don't believe it started until after I was into my residency) is
Scutwork.com (this link will take you to their psychiatry residency program listings). It is basically a site with links to all of the different residency programs, and then people can post comments about each program. They did a promotion when they first started their site giving away free shirts to people who wrote reviews - so I think most programs got at least one or two reviews explaining a resident's perspective of their program.
I really don't know how current the stuff is though.
As for what factors to consider in a psychiatry residency program:
1. Pharmacotherapy training - I mostly agree with the above post that any program will teach you med management. My own sense is that programs with good "med management" training are those programs with a heavy emphasis on empirically based treatments / evidence based medicine. My own thought is that the key isn't to learn the specific medicines of choice (as they change all the time), but rather understanding how to go about evaluating which treatments are currently the best options, and then knowing how to think through which treatment is best for a specific patient.
2. Psychotherapy training - depending on what type of practice you think you'll have will help you decide how important this is. More and more psychiatrists in practice are doing pure med management and little if any psychotherapy. It's a result of the market forces at present. There are some psychiatrists who do more therapy, but my own sense is this is a minority - my own training at a biologically based programs probably biases my view. The important things to find out are how many psychotherapy cases you'll be able to follow, and how many hours of supervision you should expect to get during that time. Also, you'll want to make sure there are some people who have a good reputation for teaching and supervising therapy.
3. Training in diagnosis - this is something that doesn't get talked about much, but it is actually the factor that I personally feel is probably most important. My own sense is those programs with a strong biologically based program are going to be stronger in teaching / supervising diagnosis of different disorders.
4. Good mentors / supervisors. You want to go somewhere where you get to work with and observe how good psychiatrists work.
5. Research - if you want a research career - the above means little relative to who you get to do research with
6. Lifestyle factors - for many people, this winds up being a primary decision maker. People want to go to a program where the calls are not too busy, and not too often. Also, some people want to know they will have a lot of opportunities for moonlighting to help pay off those med school loans. I think it's very important to go to a program where the residents like their residency director. In general, your life will be much happier at a program where you know your program director (and other mentors) will support you during tough times.