Technically that's still incorrect. XNA is not a game engine, XNA is a framework. (that's still not entirely correct, but I'm not going to go into the whole XNA vs XNA FX vs XNA GS here)
Also, Creator's Club allows you to put your game on Xbox Live Indie Games, not Xbox Live Arcade, so your target platform is not XBLA.
You should also encourage your readers to use XNA Game Studio 3.1 instead of 3.0
You should really do your research before you start teaching others, because otherwise you might teach them bad/incorrect things.
I know english is not your native language, but you should really try to have correct grammar, especially verb conjugations, which are wrong all over the site. I'm not saying your grammar should be perfect, but it should be decent at least.
I don't want to discourage you, and I'm sorry if I seem harsh, but if you want to help people, make sure they can understand what you have to say, and make sure that what you say is correct.