Instructions
Find a reputable dealer. This is especially important if you have little or no experience using telescopes. Be willing to spend time asking and answering questions. Stores that specialize in optical equipment depend upon return business and are usually willing to take the time to make sure you get a good fit with your equipment.
Determine your needs. If you travel frequently, a reflector telescope with a Dobson base is easy to carry and set up. It is not suitable for astrophotography though. A compound reflector or Schmidt-Cassegrain telescope with a computer-driven tripod mount is ideal for photography but easily damaged when traveling and takes time to set up properly.
Inspect the instrument's construction. Mounting points should be made of metal, not plastic. Barrels made of aluminum will adjust to temperature variations more quickly than thick steel tubes. Focal length adjustment mechanisms should be made of metal. Avoid any telescope that uses plastic for any moving part. It will fail at some point.
Inspect the telescope mount. Tripods made of aluminum are lightweight and easy to carry. Be sure the aluminum is a thick-enough gauge to withstand repeated setups. Inspect the tripod's adjustment mechanisms. Again, look for plastic in the support and adjustment components. Avoid tripods made of wood. They are usually made with inferior materials and are difficult to secure in a fixed position.
Look for flexibility. A high-quality telescope will offer a variety of eyepieces, mounting options and filters. A good telescope can last for years. Manufacturers realize that as your interest grows, your desire to expand the abilities of your telescope will as well. One sign of the manufacturer's belief in the quality of its product is its willingness to stock accessories for it.