I make guacamole all the time.  I make a bunch of different kinds of guacamole.  It depends on what I have around, what I am using it for, and of course what kind of mood I am in.

2 very ripe avocados
2 lemons
2-3 garlic cloves minced
green onions

Cut the avocados in half, take out the seed, and using a spoon, get out the flesh.  I use a potato masher for this job, but you could easily use a fork, a food processor, whatever your weapon of choice is.  I like mine to have some texture, so I leave some lumps.  Add the garlic cloves, green onions, lemon juice (start with the juice of one lemon) and salt.  Stir it up and taste.  I usually have to play with the salt/lemon juice ratio a bit before it tastes right.  Also, it is a good idea to taste it on a chip to see how the whole thing will taste together.

You need to eat this pretty soon after you make it.  The avocados will oxidize and turn brown on you.

That’s it.  Simple and delicious.