#3 I like the clean style of the symbol, but I can not quite make out the people and the box/book. To abstract. Mentorship is about aiding and to transfer knowledge - but not as much as teaching. A mentor "is there for you" if you need him, to ask advanced questions. The symbol is green, and it might blend in to much with the green background on the webpage.
The text for the logo is a bit to common and plain, but with good readability - which I like.
#2 Can not really understand the black dots. Heads with a cap? Looks a bit more like a car-brand, but I like the good contrast and the use of modern coloring. Still the text logo is a bit plain and common.