Model Types
Making the choice to build a remote controlled glider is only the start of the process, the next big step is choosing between buying a kit or scratch building your plane. If you're a beginner at remote controlled flying, a kit is the easiest way into the hobby. Building from a kit will give you extensive knowledge of the construction of your glider and prepare you for maintenance and repair needs, without your having to cut parts to measure or choose the proper materials.
When choosing a kit look for one that's simple to construct, and easy to control. Choose an aircraft kit that features a thick, flat bottomed wing, which will give your aircraft a low sink rate letting you retain altitude longer. Purchase an aircraft with a design that features a rudder and elevator rather than ailerons to control direction for smooth gentle turns. Find a kit that features a simple to build fuselage with a low number of total parts. A good beginner's kit is the OLY II kit from Sky Bench Aerotech, which in addition to being easy to build and durable is a good sailplane on which to learn the particular skills needed for glider flying.
If you choose to scratch build your model, you'll have a vast number of model plans to make your choice from, most available at your local hobby shop. Look for model plans that suit your anticipated flying conditions best. If you're going to be operating in a hilly area, a slope airplane that can be hand launched from a hilltop may be your best choice to build. For flatter areas, choose a thermal aircraft, designed to operate by using every bit of lift it can find on the wind as possible. Whichever plan you choose to build from, build your aircraft with light weight in mind. Any unnecessary additional weight will just drag your glider down from the skies faster.
Model Modifications
There are a few modifications you can make to your aircraft that will increase its durability and flight characteristics. One of the best methods for adding durability is to substitute spruce for some of your balsa parts. This works especially well in the wings, making them better able to survive handling and especially landing.
While lighter is typically better when building your glider, control is even more of a factor. If your glider is too light, you may have difficulty controlling it in windy situations, needing to dive in order to make turns. To deal with this issue, you can add a bit of ballast to your plane. Lead or brass weights make for easy to obtain and use ballast. Just secure inside the fuselage or wings, taking care not to unbalance your plane. If used, go lightly on the landings. A plane weighed down with ballast may take damage on landings that would do little to no harm to a lighter aircraft.