I did not Fiberglas mine. I used 3 coats of CPES (Clear Penetrating Epoxy Sealer) and 3 coats of Uniflex 255 Aliphatic from the Rot Doctor. The Uniflex 255 Aliphatic is no longer available, and he suggests using ColorCoat Aliphatic in its place.
http://www.rotdoctor.com
The CPES actually makes the wood much harder than it was, so make your cuts before you apply the CPES!
If I were to find any fault with these products, it's the shelf life. It's only about a year, and this stuff is expensive. Makes it hard to keep any around to do touch-up.
Like Bobhenry says, there are as many opinions as there are members. Pay special attention to what did NOT work (Bondo, for instance, is something that has failed for many members).
My big mistake was being in too much of a hurry. Have a plan, and though it may change as you go, always be thinking of the ramifications down the line of what you are doing now.
Again, this is the place to ask your questions!
Have a great time. I look forward to meeting you at a gathering some day.