High bar and narrow feet tends to shift things toward the quads - generally feels more natural for the tall.
Low bar and wide feet tends to shift things towards the glutes and hips - generally feels more natural for the short.
Of course there are tons of combinations/variables, and individual experience will vary a lot.
Would second Rocksteady's recommendation of the Rippetoe book if you want to actually understand it. Alternatively, look up Dan John and 'goblet squat' and do some work with dumbbells to get your own personal pattern/technique worked out.
Flexility in the ankles and hips tends to be a major limiting factor at first. Don't force it as you can end up rounding your back and risking injury. Just find a good movement, experiment with different stances, get the squat as low as you can with good form, and keep trying and moving until things get easier. Think of the first few weeks as 'practice' rather than training.