First of all congratulations for getting your adsense account. It is a great feeling. Now coming back to to your question, Sukhdev sir, is absolutely right. Here are some important points related to adsense.
1) You can associate you existing adsense to all the sites where you contribute, including blogs, all the sister spider sites etc.
2) You can have only one Adsense account for given address. If you want to create another adsense account, you will have to use another Email Id and also another address where cheques will be sent.
3) No need to tell but be careful, what to post because, now you have google adsense account which be be hampered if you don't follow the practises(like copy pasting, posting objectionable contect etc).
4) Keep in mind all these points and you will rock the internet.