You need a team of people that you can rely on and trust throughout the campaign. These are not necessarily your best friends, but they must be people that are committed to you winning. A mix of personalities is good. You don't want people that will just tell you what you want to hear. For that, call your Mother.
I am a strong believer in building an eclectic group. About 3 to 5 people. You don't want this to be to big. Believe me you will get a lot of opinions on how you should do things. A smaller group of people is easier to work with. You want people that will be honest and truthful. These people will tell you your strengths and weaknesses. It may not always be pleasant to hear, campaigning is gut wrenching at times. You will learn things about yourself you never knew. But in the end you will be very proud.
Be sure to find a person or two that has either run for office or has been involved in a few races. A seasoned person to guide you is very helpful. If you cannot find one in your group of friends, find a person in your area that you admire and that has held office. Invite them for coffee and ask them for advice. What should you expect, look out for, avoid and definitely do. Politicians love to share with others, they love to talk (especially about themselves) and most will be happy to shepherd you a bit.
You should meet at least once a week with your team. These are your "new best friends" be sure you have access to them. I also like to find people that have different life skills. Find someone that has great connections in the business community, do you have a friend that is a lawyer (free advice never hurts), someone that likes to plan events is good. Make it a mix of men and women; believe it or not we do think differently!
Be sure you can trust these people; you want to be as open as possible. You will share many laughs together, remember have fun. November (or whenever Election Day for your race is) does eventually come.