Concerta is just a long release Ritalin, it is said to last upto 12 hrs, compared to the 4 hrs from instant release 10 mg Ritalin.

Ritalin is what you should start with, it metabolises differently for every user. It may last 6 hrs for some, 2 hrs for other. If it lasts 6 hrs for you, and you jump straight to the slow release, your body will make full use of the slow release until it is passed through your digestive system. This can be good or bad, A school student may need the medication to be active for his 6+ hr school days. If you are an adult that only needs medication at certain times in a work day, Concerta is a bad option. If taken later in the day, chances are it will be in your system at night time, this impact your sleeping patterns. Ritalin does suppress your appetite too.
You can read more about why in a post I made a while back.
http://answers.yahoo.com/question/index;_ylt=ApgkrIbnat2qyJSxlwNXUZQjzKIX;_ylv=3?qid=20090326162206AA95qWE

The other alternative is Adderall, this is also available in slow release.
Adderall and Ritalin have completely different ingredients, but have the same result. I found Adderall to have slightly more adverse and frequent side effects.
My answer, trail with Ritalin to find how your system handles it, you may only need it for certain parts in a day, so a 12 hr acting tablet may not be for you. If you require the high levels of concentration for entire days, like school or an intense 9 till 5 office job, Concerta may be for you.

Also, Ritalin/Concerta doesn’t require a specific diet like Vyvanse. The one thing i hated about Vyvanse, Acidic type foods and drinks decrease its effects.
References :
http://www.edrugsearch.com/edsblog/adderall-is-for-adhd-wink-wink/

Study saying adderall is better, for those who wants to switch from ritalin->adderall
http://www.pslgroup.com/dg/1D1B76.htm

Which, by the way, is soon to be off patent and available in generic.

~Dr. B.~
References :
http://finance.yahoo.com/news/Delaware-Court-Rules-That-prnews-14803090.html