I'm afraid I don't have any direct experience in this area, but I serve client's in the Lifestyle and I've educated myself through the available literature. Some people tell me that their lives have been greatly enhanced by the experiences but others have very negative experiences. I think the ones that had the negative experiences are the ones that didn't ask the questions you just did.
The first time I went down a whitewater river, I did it with someone who was extremely experienced. I think the same concept applies here. An experienced guide helps you avoid the danger areas and is there to help if you do get in trouble. An experienced person whom you trust can make the difference between a pleasurable learning experience and a miserable and tense experience. Now, I'm one of the experienced people who shows other people the river and helps them avoid the danger areas. From the people I've met in the swing community, they're generally very willing to be helpful. I bet if you ask a couple who is experienced they would be glad to help you and she feel comfortable. The horror-stories from swinging I know of generally happened when people were just trying it on their own and I kind of suspect an experienced couple could have averted the problems.
One way that experienced swingers recommend is having an experienced couple start the evening by interacting with each other. As people get more aroused, often couples begin to play with each other. Then the more experienced couples can draw other people into the experience.
Some of the literature basically makes it sound like group sex is the answer to all life's problems and has no risks. I really respect Dan and Jennifer's videos because they lay out the risks as well as the benefits.
Society for Human Sexuality has some good information as well. I would steer you away from some of the books on the subject because they tend to be written by "salesmen" for the lifestyle.
I want to complement you on having the forethought to get information before you launch into this. Please let us know how it works out for you.