Blood tests are accurate for Celiac disease, but perhaps not so much for a gluten sensitivity. My youngest has Celiac disease, though, so hopefully I can offer some good advice. If you indeed have a gluten sensitivity you will notice improvement almost immediately, but it is important to eliminate ALL sources, which I'm sure from your own research you know includes wheat, barley, rye, and likely oats.
First, think whole foods. Fresh meats, fresh or frozen fruits and vegetables, most fresh dairy, etc...these things are naturally gluten free, and really what we should all be eating.
Second, think "avoid the middle" as in, stay clear of the aisles in a grocery store...in general. Of course you can still buy certain products (a lot of Hormel products are gluten free, if you like chili, for example...Chex cereal and some others (Fruity Pebbles!) are gluten free)...but a LOT of food you'll find in the middle isn't...and just isn't good for you anyhow. Again, there are still your things you know are gluten free in the middle...cans of tuna, etc, you get the idea.
Good replacement products...I like Ener-G Light Tapioca Loaf for bread. We have tried pretty much every GF bread on the market, and NONE of it is "really good" compared to actual bread, but this one is passing fair. They ALL need to be toasted, or they just fall apart and have a very dry texture.
Delimex makes beef tamales that are SUPER good and gluten free. You can find them in the frozen section at WalMart, and probably other stores.
I love Kinnikinnick brand GF food...my toddler (who has CD) likes their homestyle frozen waffles (spread with peanut butter) and I buy their pizza crusts, which are actually some of the best pizza crust I've ever had. You can find the specialty foods in the health section at your local grocer, etc.
I see you are in IA...do you have a Hy-Vee? At ours, Wed. is 20% off in the health market, where all the GF food is. I save a lot of money buy only buying my GF stuff on Wednesday.
Things to avoid...okay, TV dinners. Smart Ones makes some sort of chicken lemony rice one that is gluten free and yummy, and that's the only one I've found. Obviously, anything breaded. Most soups. I have a WONDERFUL recipe for making your own "cream of whatever" soups...it's a powder base, super easy to make, and I just throw it in my casseroles. Costs me about 15 cents per use, versus paying 3 dollars a pack for GF cream of mushroom soup.
Sorry, need to get lunch on the table...if you have any questions please feel free to PM me.
(***I also want to clarify that MSG is NOT gluten, as suggested below. MSG made in some countries can "contain" gluten, so obviously should be avoided, but any product made in the USA with MSG...the MSG should not be a source of gluten. Just wanted to clarify.)
***MORE*** :) We do eat a lot of rice. That's pretty much our replacement grain for our toddler. We've tried a few of the ancient grains, but even I can't get on board with how they taste. Probably an acquired taste (that I don't care to acquire.)
I'll second what a few other people have said, too...if you don't have a gluten sensitivity or CD, a gluten free diet is NOT the way to go. Sure, we should all eat more whole foods and eliminate processed garbage, which just naturally cuts down on unnecessary gluten...but for example, a piece of true whole grain bread is much better for you than my GF tapioca bread. Same goes for pasta...most GF pasta is made from rice or corn and the true whole grain pastas are better for you. So there is something to be said for testing...if you don't NEED a GF diet, don't do it. It's not a fad diet. I hear so many people saying "Oh, yes, I'm GF because it's so healthy!" when they should say, "Oh, I cut out processed garbage because it's so unhealthy!"
(Also, not saying this is you...you sound like you have actual concerns so I would go ahead and try it. If you feel better, stick with it!)