time for new brakes/rotors?

[toad]

i put new wheels on my car a couple weeks ago and never noticed the condition of my brakes with the hubcaps on, but........wow

anyways, the rotors look rusted and i sort of hear a slight grinding noise just when coasting - not braking. in fact, i never noticed any sounds when braking and maybe i'm imagining it, but i'm thinking maybe the open design of the wheels makes it easier to hear things vs. the stock steelies/hubcaps?

my question is do i need new brakes/rotors? the car has just over 100k miles and my wife and i take it easy driving, but it has been used in the past for delivery(lots of starts and stops).

i always figured i would hear some sort of squealing when the brakes need replaced, but i don't recall ever hearing that. i just think that 100k on a set of brakes might be too long, but i'm not sure? if so, is it a diy job? i've changed the springs on my 3 door and do all the routine maintenace stuff(ie. oil/filter changes), but i've never done front brakes before. just looking to save a little cash this time of year. thanks!