Is it too late to efile '08, '09,'10 taxes electronically. Will there be penalties and fees??if so how much?

It is too late to efile '08 and '09. You can still paper-file these returns and mail them in. You can efile '10 returns until mid-October. If you owe additional taxes for one or more of those years, you will have to pay interest and penalties. The amount depends on the total amount owed. If you are due a refund for any given year, there will be no interest or penalties for that year.