Looking for direction this Advent season

As I prepare for Advent I'm searching for ways to bring the true meaning of the season alive for my children. I want the next month to include activities beyond the mall photo op with Santa (which I've managed to avoid thus far) and driving around aimlessly looking for another house decorated ala Clark Griswald.
It's hard with three children four and under (now you know why I don't post more often) to plan anything too deep and meaningful no matter what interest my husband and I have. (All the museums we've been to in the last year allow lots of touching.) Furthermore, we try to find the most child friendly ways of introducing and enjoying 'deep' Church practices. For example, while my husband loves the two hour high mass at our traditional rite church, we usually attend earlier low mass to keep our sanity. And I would love to have a nice large Advent wreath with nice tall burning tapers, but for now, we have a safe cloth and Velcro version with bright yellow felt flames. No midnight mass this year either.
The local free family actives paper I pick up at the grocery store listed volunteering ideas for families to under take this "holiday" season. Giving is natural part of Advent and Christmas (and the Gospel in general) but how to convey the importance of charity to such young children? Most of the paper's ideas focused on sending items/money to sick children, troops overseas, impoverished families, etc. via a major organization. So it's charity, without actually having to meet or interact with anyone. There can be some correspondence between donators and recipients but it's minimal. It's a step in the right direction and hopefully it leads people to a more hands on role. Ultimately, I'll probably try some of the recommendations this year with my own brood.
My struggle is how much do I expose my children to at such a young age? Mailing cards to sick kids or visiting sick kids in the hospital? I don't want my children scared of coming down with a terminal illness. Do I take my kids to downtown Camden to help serve Christmas dinner? At what point is safety a factor? It's also the dilemma I face in becoming Worker in general. My children are my first priority. I want them to grow up with charity as second nature; where serving in a soup kitchen will be no different then playing on a sports team. But I'm having a hard time finding the balance between raising the kids and giving my time to the needy. I don' t want to wait until they're out of the house because then it's too late to instill the importance of doing charity. However, I don' t want it to become just another occasional event penciled in on the weekends or holidays. I want to be a Worker family 24/7 but how do I give everyone all the attention they need without anyone, including myself, getting shortchanged? Did I mention I homeschool? Hopefully during Advent, a time of personal reflection, mortification and penance for me, I can come up with some answers and direction.