To answer the initial question about why we need guides, the analogy mine gave me is that a plant can grow wild on its own, or it can be cultivated by a loving gardener. The latter plant is likely to be much more healthy and beautiful, and the relationship brings great joy to both.
Some people's life experiences involve working with their guides and some do not. We do have a huge spiritual "team" working with us and for us of which our guides are really just the forward representatives. My guides came to me "at the right time" and that was after many years of loneliness and struggle in my life. Once I had waded my way, very slowly and with great difficulty, through my emotional issues by myself, they turned up and were all "OK, well done, we're going to help you from here on." There were certain things I had to learn on my own and now there are certain things I now need to work on with my guides. Depending on the intentions with which we arrived in this life, we may need to do things with a limited amount of guidance from them.
The work of a guide is going to vary massively from person to person depending on their needs, so there's really no way to say "this is what a guide does". The personalities of guides and preferred methods of working really vary as well and they all have their own specialities. There seem to be many different kinds of relationships with guides, too (from teacher-student type relationships to informal best-friend type relationships - I like to have a cuddle-pile with mine!
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