I'm about to start eleven months in DC, and there are a ton of things I've come to learn about my local area....which would have been nice to know before arriving.
First, for safety purposes....once you cross the river from Virginia into DC.....you are basically in a zone of conflict. It'd best to describe it as that place where Kurt Russell was dumped off into and told to recover the President, and had to fight his way out. On any given day, some lady could come up to you near a coffee shop, and stab you in the back....and not even mention a word about your looks, your billfold, or your political feelings. Heck, you could be at a funeral at 1PM, and get a few guys riled up enough to shoot you as you drove off in a car.
Second, while most folks think that Mexicans are the predominant Latino group in America....if you live in the DC region....it's the El Salvadorian guys. Ninety-nine percent of them are friendly folks....the other one percent are affiliated with the M-13 cartel guys.
Third, forget about finding a Super-Wal-Mart in the area. You've got a fair drive, and just accept it.
Fourth, tourism is a major deal. The amusing thing is that after you've been here sixty days and know the layout of the area....tourists actually start asking you questions on where things are.
Fifth, METRO carries an amazing number of folks around the area on a daily basis. It's mostly a miracle that it runs as well as it does and accidents are just a monthly thing. Learn to accept METRO and ride as much as possible to lessen the stress of parking and getting those $129 'boot' tickets.
Sixth, coffee consumption is a significant part of your life in DC. If you were drinking two cups prior to arrival....you will be drinking four cups after arriving. And you won't even pause when the dopey coffee lady says 'six buck' for your double caffein-double maple El Grande cup of coffee.
Seventh, just a plain vanilla studio apartment will run $1000 a month within the region of DC. If you live twelve miles south....you can get a $850 two-bedroom apartment. The question is....do you want to battle the interstate in getting into DC each day?
Eighth, if you eyeball a map of DC and look slightly to the right and down...within the district....then draw a big red circle around that area.....you'd best avoid it in daylight or evening hours. Don't accidentally come off the interstate or get off at the wrong subway station.
Ninth, the general basic package for cable TV consist of 100 channels. To be kinda honest....eight of them are of value, and the other 92 are worthless.
Tenth, on a typical day at a mall....stand and count foreigners....and then accept the fact that four of ten folks are first-generation Americans at best. Yes, you are a stranger in a foreign land.