Every time I turn on iMessage my iPhone ask me to enter in my apple id password,I was previously jail broken and was curious if this normal.especially since I won't put in my password and iMessage works
Other than having iMessage enabled in settings with your phone number (on the iPhone) and an email address (iPhone and iPad) ... there's not a way to "turn on" iMessage. It's automatic in the messaging app.
The app automatically will send a text message as an iMessage to an enabled iDevice ... or as a regular SMS to a non-iPhone. iMessage can go to a iPhone via phone number or email address. It's email-address-only connection for the iPad.