Heavy duty jack stands, quality hydraulic floor jack, (not one of those cheesy little things with the removable pipe handle) and a level concrete floor, is a must.
Light weight jack stands, cheep jack, blacktop, gravel or dirt is just asking for trouble.
I always jack up the front first. I place a short 2x6 flat on the jack so it fits center of the K frame. I place the jack stands on the lower control arms, close to the lower ball joint.
Then I'll place the floor jack under the center of the rear housing and jack it up. The rear is lighter than the front and works better than lifting the front with the rear in the air. JMO
Like stated when jacking, make sure you see the wheels rolling on the jack. If they don't, it's about to jump off. It only takes a little piece of something under a wheel to cause this.
If you're going to let the rear hang, like some cars need just to remove the wheels, place the jack stands in front of the spring hangers. There's solid frame there that will support the weight.
Once all four stands are supporting the weight, put some body weight on each front fender to settle the suspension. Do a good inspection on the stands one more time before going under to do any work.
One thing I always do when removing wheels is I'll throw the removed wheel under the car for a safty just in case something would slip. It could save you from getting trapped between the floor and car and will allow you to get a jack under there again.
Safety first!