Quality hunting knives typically have either carbon steel or stainless steel blades. Each type of blade has advantages and disadvantages. Carbon steel blades rust, so they require special treatment. Regular use is the best way to prevent rust from forming on the blade, but you can also coat the blade to prevent rust. To coat your carbon steel blade, clean your blade thoroughly, allow it to dry completely, then apply a wax that contains silicon. Waxes made specifically for this job are available. Once it's coated, the carbon steel blade should be resistant to rusting. Carbon steel blades tend to be easier to sharpen and remain sharp for longer than a stainless steel blade.
Stainless steel knife blades are rust resistant. This makes them extremely popular with hunters who hunt in areas with rainy conditions. However, stainless steel knives are more difficult to sharpen and more expensive than carbon steel knives.
If you're interested in a folding blade knife, examine the pivot point thoroughly. This is the area that will be under pressure as you open and shut the blade. Also, check the locking mechanism -- if this fails, it can cause a nasty accident. A quality blade, a sturdy handle and a strong intersection of the two are all important points in both a folding and fixed blade knife.
Whether you choose a fixed or folding blade knife, the handle should be sturdy and feel relatively heavy in your hand. Examine the area where the knife's blade enters the handle -- this can be a point of weakness. If you choose a folding blade knife, check how the blade folds into the handle. Does it line up and move relatively easy, or do you have to force it? A quality knife should move with ease.