So you're ready to jump into this world, huh? Well, you need to stock up on a few things if you're going to stick with it. Below is a list of supplies that I recommend you stock up on before you start building planes. I also included explanations so you can make a more informed decision as to whether or not you need a particular item.

DISCLAIMER: I don't make any claims that any of my advice is good and/or accurate. This information is knowledge that I've picked up along the way and has worked for me and/or for other people. If you ruin your plane because of something that appears in these pages, I take no responsibility for it.

DISCLAIMER: The web sites that I refer to are there simply for reference and are in no way, shape, or form an endorsement for the site and/or the company that owns and/or manages the site. I provide these links so that you can see what I'm talking about and get an idea of what to purchase.

Necessities
CA Glue (5-15 seconds) Similar to super glue, works for most surfaces. Dries extremely quickly!
Uncure (30-120 seconds) Undoes what CA glue does.
LocTite/Thread Locker You don't want your plane coming apart in mid-flight, do you? LocTite or Thread Locker is like a glue for nuts and bolts.
Epoxy (5 minute) Some parts require more strength when joined than CA glue offers. While CA glue is strong, epoxy can't be beat. Usually it'll come in a package that has two tubes. The contents of each tube has to be mixed with the other to make the adhesive compound. Epoxy can be messy (as can CA glue) so be sure to get some shop towels as well.
Epoxy (30 minute) If you're taking your time or need more curing time.
Popsicle Sticks Use these to mix epoxy.
Disposable Bowls Use these to mix epoxy in.
Applicators A generic term. Use these to apply epoxy to the parts of the plane that need to be joined.
 
 
Additional Recommended Supplies
High Temperature RTV Silicon Gasket Maker Over time, it is quite possible that the muffler/silencer will discolor. By using this on all the cracks and holes, you can prevent this from happening. I don't know all the details of how it works, how to apply it, or where to apply it, so take this at your own risk. I was told by several seasoned pilots this works if you do it right. (See my disclaimer above about ruining your plane.)
E/Z connectors See the Tips page to learn more about these. In summary, these make it easier to adjust the pushrods on your plane.
Wheel Collars The collars that come with your kit should be sufficient. You may want to have a few extra in case you strip any of them while tightening them down.
Lead Weights Your plane has to be as perfectly balanced as possible. These weights can help balance your plane if it's not once you've assembled it. There are different sizes you can purchase. I'd recommend getting the smallest size so you have more control over the amount of weight you can add to the plane.
Cap Screws See the Tips page to learn more about these. When using screws, always try to use caps screws.
Fuel Tubing You can't get enough fuel tubing. Not only are they used for fuel lines, they're also used to secure pushrod connectors.
Brass or Aluminum Tubing If you're like me, you'll probably break the aluminum tubing that comes with your plane kit. That's okay, it happens. But you need to replace what you broke. Having extra tubing on hand is not a bad thing. Be sure you have the right diameter since the fuel tank stopper assembly is drilled out for a particular diameter.
Thin Pieces of Wood Two thin pieces of wood rubber-banded together on one end can be used to center the various control flaps on your plane. Using a C-clamp, you can LIGHTLY clamp the other end of the two pieces of wood around the flap (for example, the rudder) to center it before mounting and adjusting the pushrods.

As I gain more knowledge and experience in this great hobby, I'll update this list. So keep checking back occassionally to see what new and exciting items you can buy!