what's looked at?

<p>i am a junior right now and i was wondering,
as far as grades and extra curricular activities, what is it that colleges look at?
i was told by a friend that they look at your junior year the most, which would be great because i'm doing better and involved more in school than the past two years. i'm currently in the top 10% of my class (unsure where) and have about a 3.95 or so GPA (unweighted), having taken honors and advanced courses since 8th grade and my first AP class this year (bio). However, my freshman year i was only involved in one extra curricular activity and made my first B's (4 of them). I also did not begin school related service/volunteer work until this year.
will this hurt me when colleges consider me?</p>