Letters of Recommendation

I plan on transferring to Boston University (http://talk.collegeconfidential.com/transfer-students/1797927-community-college-to-boston-university.html#latest). I have three professors that would write letters for me gladly if I asked. My social psychology professor already said yes. However, he didn’t want to meet with me about it so I’m hesitant He just wanted the requirements. The other professor is the chair of behavioral sciences at my college. I emailed her today. I’m sure she’ll do it. She taught Child Psychology before becoming the chair which happens to be the area I want to specialize in. I’m also hesitant about the third teacher I had in mind since I only got a B due to flopping on one test. However, I always led class discussions, etc. I think she really liked me! She taught an intro to behavioral research class. She is also a Boston University graduate. My final paper in her class was amazing and received an A. She loved it.

Do letters from alumni of the school they’re writing to look better/good? I’m planning to meet with the BU alumni and feel her out. I’ve never had letters of recommendation written for me. What kind of questions do I ask them? For example, what should I have them place emphasis on, etc? I’m a psychology major. What are your thoughts?