Well, just from my perspective, which isn't relevant at all to weights but maybe will spark some ideas - I like calisthenics & I don't have much room right now for exercise equipment, plus I'm busy & hate going to the gym anyway. Here's what I use:
1. Stepper: (cardio) $58 shipped
http://www.amazon.com/gp/product/B0016BUR7I
2. Pullup bar: $24 shipped
http://www.amazon.com/gp/product/B001EJMS6K
3. Yoga mat: I have carpet, but if you have hard floors, it'd be worth investing in either a thick padded yoga mat or a rug so you don't kill your joints & stuff if you're doing calisthenics on the ground (pushups, squats, etc.).
My buddy has a pretty sick dip station; there are tons of crazy power towers available like this one:
http://www.amazon.com/Weider-WEBE99712-Power-Tower/dp/B0098MAYNY/
The stepper looks dumb, but it will kick your rear haha. I use it when I watch TV (my Roku 3 has a remote control that lets you plug in any headphones wirelessly, so I can workout anytime I want but keep it quiet for the family). The pullup bar has a little hook you attach to the doorframe, so it's actually pretty strong. At my peak, I was 240 & it was able to hold me just fine without breaking my door. I have a space next to my bed that is carpeted where I do my pushups & stuff. Right now I just use a fold-up chair for doing dips & whatnot, no need for a fancy dip station at the present time.
If you like free weights, you might consider a kettleball or two (bonus of being more portable too). As far as benches & weights go, Stronglifts has some good info on safety regarding benching without a spotter:
http://stronglifts.com/bench-press/safety/
As well as an equipment buyer's guide:
http://stronglifts.com/home-gym-equipment-buyer-guide/
If you're exercising by yourself, there are tons of articles to read up on for solo workouts & how to do them safely:
http://www.muscleandfitness.com/training/routines/flying-solo-workout
Lots of weight guys here can chime in. I'm not on the calisthenics & cardio side of things, but those are nice tools too to start out with. Congrats on the start of your home gym!