1. To quicken ripening speed, place the avocados alongside a banana. It's even faster if you pop them in a brown paper bag. Bananas produce ethylene hormone in excess as they ripen which in turn ripens the avocados lying next to them.
2. I'm not one for throwing unripe avos in the freezer, it's never worked for me. You can, however, pop RIPE avocados in the freezer, so long as you take the skin off and the stone out and wrap them in clingfilm. Another alternative is to mash them up (my preferred method) -- squeeze some lemon juice on the pureed mix and store it in the freezer in a resealable bag or again, in clingfilm. This will allow you to make guacamole long after the avo season is over but not avo toast, as the texture is affected by the cold.
3. Avocados should be kept out of sunlight at a temperature of between 65°F - 75°F / 18°C - 24°C. If you've ended up with too many ripe at the same time, put a few of the RIPE avocados in the fridge for a few days as this will give you extra days until they have to be eaten.
4. Do not put an unripe avocado in a very cold fridge as this will affect the ripening process and you'll probably end up with a weird, wrinkly avo. However, if you must pop them in a fridge because you've bought too many, make sure it's on a medium setting and always place them in the vegetable drawer. Take out after a couple of days. Refrigeration dramatically slows the ripening process and can affect the fruit so that it never really ripens properly. Think bananas -- they never go in the fridge unless they've gone so ripe and black that you're keeping them to use in a cake instead of eating them directly. Avocados that come from the other side of the world often taste odd and have a nasty texture because they have been kept too cold during transit as they sail in containers across the seas or overland in refrigerated trucks.
5. Give the avocado on your countertop a gentle squeeze to see if it's ready. Some avocados, such as Hass, have a harder skin which makes it difficult to tell if they're ready to be eaten so you will have to go on feel and skin colour change. Others, such as Fuerte, Pinkerton, Gwen, Reed and Bacon (to name but a few), remain green, so it's entirely through touch that you'll find out if they're ready to be eaten.