98 Lumina - replacing brake pads

Forgive me if this seems like a total newbie question, but when should I replace the brake pads and/or shocks on a 1998 Lumina?

Both the brakes and shocks were new when I bought the car in September 2003. I average about 150 miles/week, evenly split between highway night driving and daytime surface street driving, and have put about 10k miles on the car so far.

The front brakes squeak a little when I pull out of the driveway in the morning, but are otherwise silent. The ride feels a little bumpy and floaty, but I can't tell if it's the bad roads up here, me getting used to how the car handles, and/or shocks in need of replacement.

Any input would be appreciated.

push on each corner of the car and get it buouncing. when you stop pushing, it shouldn't bounce more than once then stop. If it bounces more than once, you need struts on that end of the car. Always replace struts in pairs, so if the right rear (for example) keeps bouncing, replace both rear struts and mounts. The brakes are a little more tricky. Without taking a wheel off, it's impossible to determine whether they need replacing, unless of course they squeak every time you apply them, or start to grind, which means the rotors are toast too.