Boxer briefs for sure.  I usually get them at American Eagle, but Hollister has some nice ones too

Adam Archuleta has been my favorite for a while now!  ;D

On my right side usually  ^-^

Definitely varies for me.  Some weeks I jerk off once a day.  Other weeks more like 2-3 times.  When I was in high school, sometimes 5 or 6.

When I was 15 I was at a pool with a bunch of friends.  The guy I had a crush on, Tyler, was there swimming, and I finally just went to the showers to jerk off.  It had a pull curtain, and no one was around.  When I was getting close, Tyler came looking for me and noticed me behind the curtain.  I pulled my trunks up and went out, not having showered and with an obvious boner…  We were both very embarrassed and never really talked about it.  I like to think he was a little excited when he found me.