Last year was my daughters first year (2nd grade). I think it depends on the troop leader. My daughter usually has one troop meeting a month and then in addition to that they have various outings or field trips. All of the field trips are optional, however, they usually earn a patch for each outing so we try to go to all that she's interested in. As for the cookie sales, those usually take place in January or February. Last year we only sold to family and friends, but I know some troops will set up booths at local businesses on a saturday or sunday.
Just to give you an idea, we have an upcoming hayride, a field trip to a business that screenprints t-shirts, an overnight trip to a planetarium (sp), and in December we do a day of community service at the senior center. There was also a field trip to the Parade Company in Detroit that we missed out on, and last weekend on older troop put on a day (3 hours) of activitites for our troop which helped them to earn 3 badges.
All in all she enjoys it. She's in other activities (dance, running club, religious ed, tennis) and she has 3 younger siblings so when it gets too much or we can't make it we'll just not do it...no guilt.
I will say though, this year I am homeschooling my kids and because of that we have much more free time during the "after school" hours. There is no way we'd have time for all of the extra activities if she was getting off the bus at 3:45, tired and grouchy with homework to complete.
Hope this helps and that I haven't totoally confused you.