Wow, I'm starting to feel like I need to come "out of the closet" about wanting many kids. It is SOOOO nice to see other people feelign the same way. On another board I'm on I asked how people deal with commenting on how many kids you have. I am single and have 3 boys under the age of 5 and hopefully have a newborn boy coming within a month or so. I love and want many children. All my children are foster children so I don't have any discussion about birthing more children.
My feeling, though, is that so many people, and society in general, has gotten so much into the whole "both parents have to have an outside-the-family-career and LOVE it and have very few kids." GREAT. If that's what you want, there's nothing wrong with having 1 or 2 kids. I want 4-6. I get comments at almost every turn. There's almost nowhere I go with my brood where I don't get comments. Now, all of the comments are good and admiring and all, but people don't realize how tiring it gets with everyone thinking that you're some kind of superhuman (read inhuman) person to be able to deal with many small children. It really ain't that hard with a bit of organization and practice. I am usually sitting down in my living room by myself on my computer or watching TV relaxing by about 7. Everyone bathed and fed and pajamed and the younger ones sleeping and the older one playing. As someone said on my foster parent board, after 3 kids all you notice is more laundry!
As for details, you'll need a car (minivan) that can hold all the children safely and enough beds, etc. My food bill is higher than it was when I had no kids, but it doesn't increase all that much with additional kids. Plus, everything I own is put to good use. Every sling, stroller, toy, clothing, etc. gets many loving uses, not just 1 or 2 kids then gotten rid of. Money seems to be a problem mostly if all parents work or if you're on the edge of poverty. If you can handle the extra child care costs for a few years OR stay at home then money isn't a big deal.
When people ask how many to have I say if you're dying to have another kid around DO IT! If you feel like your family is complete then stop. I have 3 and am DYING to have another one. We'll see where it ends...