To submit your application to the Android Market, you must have or create a Google account and sign up as an Android developer. You also must pay a one-time registration fee of $25 (see https://market.android.com/publish/signup).
You should read the Android Market Developer Distribution Agreement (http://www.android.com/us/developer-distribution-agreement.html) as well as the content policy which determines what content is allowed (http://www.android.com/market/terms/developer-content-policy.html).
If you are going to sell applications through the Android Market, you need to set up a merchant account with Google Checkout.