"Are there any other places for good , not expensive shopping for a whole family (not souvienirs) clothes, shoes for men and women and children."

Pentagon City is accessible by the metro and has the best selection of stores given what u stated u are looking for. Your hotel is about 2-3 blks from the metro Blue Line. You can take that to Pentagon City...maybe a 10 minute metro ride.

Its also worth checking out one of the Filene's which has discounted clothes for children and adults.

Mazza Gallerie is more high end -- Neiman Marcus is the big dept store there. Chevy Chase Pavillon across the street from Mazza Gallerie is a smaller mall and has way fewer stores than Pentagon City.

Tyson's Corner is a very large mall, but I would not spend the taxi fare or take the time to get out there with other options much closer.

I agree w/ suggestions to just go to Pentagon City Mall. It's quick, easy, convenient (has a Metro stop), and has LOTS of varied stores. They will have anything you are likely to need.

Again and again thanks to all of you for your help.
Now I am trying to find out how to use the metro in DC.
I have been in Switzerland for many times, and to be honest the public transportation system there works very timely, and is very safe. I am from Armenia, but I have been living in Russia for 2 years, I am not sure that using the metro for the foreigner in Moscow or in Yerevan is really safe (a lot of thiefs ). That’s why I was not thinking of travelling in the DC by a metro system. But if it is really safe, why not?
Also many of my friends advised me to do a lot of shopping in DC, as they have told me that everything is much cheaper in US than in Armenia or Russia. Thant’s why I was asking an advise for shopping places

The Metro in DC is very convenient and safe.

The way the metro works in DC is you buy a ticket with a certain amount of money on it (you choose the amount). You put the ticket in the machine when you enter, and again when you exit (and it electronically deducts the amount of your trip). You can add money to it at any time (it'll actually print a new card), or, if you try to exit without enough money on the card for that particular trip, you just go to the "add fare" machine to add the exact amount you need. I believe the machines do take credit cards (at least the ones in San Francisco do - and its the same system) or cash, and they do make change.

DC's metro is very safe and convenient.

Someone above mentioned:

"Mazza Gallerie is more high end -- Neiman Marcus is the big dept store there. Chevy Chase Pavillon across the street from Mazza Gallerie is a smaller mall and has way fewer stores than Pentagon City."

Just FYI, the Mazza Gallerie shopping area described above is at the Friendship Heights stop on Metro's Red Line.

You specifically mentioned shoes. Note that right next to the Pentagon City Mall is another shopping center called Pentagon Row which includes a DSW Shoe Warehouse, among other stuff:

http://www.pentagonrow.com/shopping/

You can purchase metro fares online with a credit card
http://www.wmata.com/fares/purchase/
I don't think you can buy a farecard at a metro station with a credit card. The machine will give you change, but it's best to use smaller bills as your change is returned in coins only. If you have a $1.35 fare and u put in a $10 bill to pay, you will get $8.65 back all in change.
They do have attendants in a booth who can help you if you have a question.

DSW Shoes has a huge selection of discounted shoes in all prices.

I use a credit card to add to my SmartTrip card. I can check to see if it is possible to use one for the paper farecard. I can't imagine it wouldn't be.

There is no need to buy your Metro farecard in advance. The ticketing machines take credit cards and will issue a paper farecard.

I was wrong, Anonymous is correct -- fare card machines at Metro do take credit cards.

About half of the Farecard machines--those with a blue front--take credit cards. The older, all-gray machines take only cash. There are both kinds of machines in every station until Metro completes replacement of all the old ones.