Noodles-mian tiao or some times just mian.
Unless said otherwise, noodles will come inside a soup:

• “niu rou mian” - 牛肉面
  
• “la mian” - 拉面

Above: a bowl of "La Mian"

When it's not in a soup it's usually fried with vegetable and possibly meat. Then it becomes “chao mian” (炒面).

Beijing has a specialty: the so-called "Beijing Noodles". It's a bowl of warm noodles (not hot), neither fried, nor with soup. Instead, they are covered with a local sauce. This very similar sauce served with Beijing Kao Ya, it's a thick brown sauce which tastes a little salty.

For eating "Beijing Noodles" there is one restaurant very well known under the Chinese. As an "insider tip", go to the "King of Old Beijing Noodles" 老北京炸酱面大王.

What makes this restaurant special, is that it is decorated in the old Beijing style with traditional Chinese tables and chairs. All the waiters are also clothes in old Chinese clothes. You can just imagine how it was to go out eating back then in the "good old times".

Adress: 老北京炸酱面大王崇文门总店, 崇文门外大街29号 ChongWenMen Wai Dajie 29

The easiest way is to go there by taxi. But you can take the subway line 5 to ChongWenMen 崇文门 Station or CiQiKou 磁器口 Station and take the taxi then (this way it will only cost you 10 RMB for the taxi)