Can I write an article about the company I work for and then post it on wikipedia?

I read wikipedia a lot but I have never edited. Do you have any tips?

I am established user on Wikipedia, and I would not put an article as the company must be significant. Also, editing Wikipedia is hard and if you mess it up you will get blocked and there is also a chance your hard might get deleted as most company pages added are considered adverts.

Yes, you can, but the company has to be significant. For example, a company which doesn't have a website wouldn't be significant, and a company with less than 10 people would also be insignificant. Also, the information that you write must already have been published before, as per Wikipedia's writing guidelines.

Check this link for wikipedia's guidelines. http://en.wikipedia.org/wiki/Wikipedia:Y...

Did you sign a non-disclosure agreement with your company when you were hired?

Not without the approval of the company management. So, No. Although you can write an opinion article on a blog, the information in Wiki has to be accurate and you will never be accurate without consulting your managers.

You don't need approval from your company to write an article on it. However, the company has to be notable (check out http://en.wikipedia.org/wiki/Wikipedia:N... for guidelines on this), and writing it yourself may amount to what is called at Wikipedia a "Conflict of Interest".