I will look up a couple of good books so that you can do some real research on the illness. Lots of times I see people genuinely want to help or be there for a person who has this illness and they do and say the wrong things because they just don't know better. Here is a link to resources on the subject.
self-help-books/ --This link has a couple of book on bipolar and I will also come back and share titles and authors of a few good books.
What I like in a good friend is that they don't just act like I have nothing. Bipolar sometimes and a lot of times dictates so much of our lives when we are in different episodes. Life with bipolar is dealt with almost 100% of the time, so to me when this is ignored, it doesn't leave room for me to share any problem I may be having. They don't say, how are you, how have you been feeling, mood wise? Are you feeling better? Nothing. So I have only the 2 friends who I can talk to and all the rest barely know or even want to know who I am. That to me is basics. If you want to be my friend, please accept me and my illness for what they are and acknowledge it as well.