Hello and thank you for using Just Answer,You certainly do not want to wait much longer. If you are due a refund from tax year 2008, the IRS is not obligated to give it to you because of the time to file (3 years from due date of the return) to request a refund.
Should you do the returns yourself? If the information involves a W2 and nothing more then you probably would wnat to just complete the returns and mail them each in. You could still e-file the 2011 return (till October) but the 2010 and 2009 returns are not allowed to be e-filed when past the extension dates.
If you have more information that you are not familiar with then you may want to get a professional to complete them for you.
Do not be afraid, unless you know that you owe. So far, you only risk not getting a refund from 2008 but the 2009 - 2011 may see you getting money back.
If you do owe, the IRS will allow you to set up payment plans for any year that has a balance due.
My best wishes for you and do not delay further.