Headed to DC in September for a week. I know there will be a lot of walking so taking the tennis shoes for that. What else should we do or experience while there? VRBO or hotel? Will we need a car?

DC area has buses and horrible parking but I would rent a car anyway and pay the parking fine if you are a min. late because the Smithsonian decides to close the exit nearest your parked car and you have to spend an additional 16 mins to get to your car that has a ticket on it. There is also hidden speed cameras for an additional $100.

But still better than the buses

http://moneyfactory.gov/

http://www.si.edu/Museums/

food

http://airandspace.si.edu/about/newsroom/release/?id=69

We're going in July - I grew up in / around the area but my kids have never been, so we are doing full on tourist mode. My kids are 10 / 13, so we are not doing a lot of the war memorials this time. We are, however, working on a Council's Own Girl Scout badge for my daughter, which is driving some of the things on our list below.

I would not bother with a car - the DC public transport system is easy, reliable, and relatively safe (be smart......) The caveat would be if you plan to take a day trip or two, say to Mt Vernon or Baltimore. You can buy prepaid metro passes online and you can take the metro straight from the airport if your hotel is on the metro line.

I prefer residential hotels so you can eat breakfast / snacks at your leisure, and possibly other meals, depending on your schedule. Consider using something like a grocery delivery service or Amazon (Prime Pantry!) and having stuff sent to the hotel.

If you want to tour the White House, Capitol Building, or go up the Washington Monument, get on those now, as you will need to book further in advance than you'd think. If you are doing other 'pay to play' items, go ahead and research ticket availability and prices.

These are the things currently on our list - we still have a pending request on a White House tour but have been warned those are hard to get approval for, so we are planning as if we won't get it.

Washington Monument (no elevator, missed the availability window)
Jefferson Memorial
FDR Memorial
Lincoln Memorial
Boy Scout Memorial
Fords Theater (not free)

American History Museum (free)
Natural History Museum (free)
National Archives (free)
National Art Gallery (free)
Air & Space Museum (free)
Constitution Hall / Daughters of the American Revolution Museum (free)
International Spy Museum (not free)

Capitol Building tour (free but requires a reservation for security purposes)
Supreme Court Building tour (free)
White House (external photo op only)

National Zoo (free)

I've been there once and want to go back again. Next time I go I will stay more in the middle of the tourist areas. Then hopefully I can walk most anywhere or take a short subway ride.

The last there I had to take the hotel shuttle to the subway station each day then head out from there.

When we took the kids and did the touristy things, we stayed at the Embassy Suites in Chevy Chase. The metro (red line) stops right at the hotel, and takes you right down by the White House. It was very convenient.

The most important thing to pack for a summer trip to DC is extra deodorant. So muggy.

We used the metro when there or walked. It was easy to get around without a car or taking the buses. The Mennonites have a bed and breakfast there for about $40 a night. Excellent breakfast plus cookies when you get back.

I have stayed http://www.marriott.com/hotels/travel/wascn-courtyard-washington-convention-center/ three times for bank related conferences only to realized that the Zoo was walking distance after the second time,

Went as a first timer a little while back and had no trouble at all with the metro - just two women alone. It's clean and available just about everywhere and oh so easy to use. We took one of the nighttime tours of the monuments that was awesome. I would do that again.

The only thing we missed that I regretted was the National Cathedral and the zoo. I love looking at churches.

Dupont Circle area is centrally located and a nice neighborhood if you can stay there the mall is a short walk . Like someone else said, it can be very humid there as is most of the east coast in summer and early fall. Enjoy, DC is a great city!

I used to live in the DC area, as well. I can think of so many wonderful things to do and see.

I would say visit Arlington Cemetery and witness the changing of the guard - learn all about it - you will never forget it.

You can get to the second air and space museum out at the airport by the light rail, it is worth the trip. It also takes you out to near the first and second battles of Manassas (or Bull Run). You are really going to have to plan because there is so much you are not going to get to.