I have written a novel based on my past life experiences, however the story involves a few people who might not like the idea of getting their stories published. What is the legal and social effects that I should consider and take care of.
As mentioned in comments this question has been addressed before but as a fellow writer I cannot resist talking about my own experiences.
I tell a lot of stories that involve my friends and family. I also (when the daylight allows) run a writer's group. An exercise I give the group is to write a description of several people in the group without using their name.
Not only do the group members find that they work differently but their descriptions are much more engaging than their regular work (showing that working from life is a good way to make art) but the group found it very hard to identify themselves from their friends perceptions of themselves. In most cases the subjects were flattered to be described even when the writer was largely unkind.
However the legal implications are a different story. You need to do enough to be able to claim that while inspired by true events and characters the story is fictional. The advice is generally that you should not name or use significantly identifiable characteristics. The test being that a reasonable person might be able to identify the subject from the work - we've shown that this is actually quite hard when the writer is not trying to hide anything.
So go read the good advice of others but also carry out some fiction writer's science. Write a paragraph description of several friends and then ask them and an equal number of not described friends to first identify the people being described. The test group will not see themselves any more often than the control group. Then tell them that they are in there and to identify their description (don't let them know which group they are in - tell them all that they are in there). I would expect you to find that the control group will pick a description out as being themselves about as often as the subject group do but that the subject group will be not be hugely accurate. You are likely to find that people find it hard to pick out themselves and friends.