I don't use Print Central so can't help you there.
Sit tight and someone will be along who can answer your question, in the meantime:
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.
simply open up PrintCentral , tap into the email tab and add your email account details, select an email and print right away! Contact their really good support team under the "i" in the app if you have any issues