The Application Process

I'm looking for good links to articles written about letters of recommendation. I'd like tips about how to "package" the request to the recommenders.

Additionally, in my current job of 3+ years (airline pilot), I don't have a direct supervisor. Instead, I work with new and different people everyday. With that said, I'm having trouble finding potential recommenders. In addition to one person that I luckily have worked with for quite a while, who else can I ask? Is it appropriate to ask an old college student-group adviser who worked with me for 3 years? I'm concerned, because he worked with me about 4 years ago, but he also knows my work very well.

Thanks for your help.