I used to work for a network engineer, so maybe I can help you.

* How easy is it to get a computer related job there being a computer science engineer?

Pretty easy - I'm sure you've heard, there are more jobs than people right now, and start-up ISPS and websites desperately need workers.

Nuria told me they don't care if your English is not perfect or if you don't have experience. Is it true?.

See above! These days, employers need a warm body and little else.

* Do I have to get a contract beforehand to get a working visa?. If so, for how long will I be entitled to work there?.

I don't know about immigration laws, but someplaces will hire you illegally, and thereby paying you less.

* Where should I go?. (apart from Sillicon Valley which is only for experts).

The US is a huge country. What appeals to you? Big cities are probably easier to live in, and definitely easier to find work in, especially if you can't get a visa and have to work under the table.

Good luck.