Bike Fitting

Ok, I have very little experience with road/tri bike riding that wasn't totally, 100% self taught. I have never had someone give me tips and such, I bought everything online before I left on a deployment a number of years ago with only a little bit of research, and was my first time using a multi speed bike.So my question is about getting my bike fit to me to optimize power and such.I come from a pretty athletic background of running and wrestling and have made some pretty good advancements on the bike since I got back on it in December, but want to ensure I don't drop $75-$100 on a kid that is not anymore prepared to set me up than my kids.How do I know the person doing the setup knows what they are doing? Is there a certification association or something? I bought all my gear when I was single and deployed 9 months out of the year, now I got a wife and two kids and spending $100 on something that doesn't pay off is the reason I haven't done it sooner.So what can you tell me to keep me from making the mistakes you did, or deal with the stuff you had to on your way to getting the bike setup for my first triathlon, and HIM this July?thanks