With drill bits, there is no "one size fits all". There are different grades (steel, carbide, diamond, etc.); and there are different angles. I know we have at least 4 different drill sets of S.A.E. drills, plus individual metric drills, left-handed drills, wood drills, etc.

Best advice I could give is to determine the type job you will be doing most often, and purchase bits for that type of job.

Heat is the enemy of longevity in drill bits. There is a correct speed, a correct pressure, and often a correct lubricant for each job.

As to sharpening bits for the hobbyist: the cheap bits can be sharpened, but I have better things to do with my time for the money. The harder, more expensive bits are more difficult to sharpen.

We consider ALL drill bits to be disposable (we don't sharpen any of them).

A machinists handbook or even a good high school shop textbook is a worthwhile read.

Jon.