For 1 egg: 1 Tbs ground flax seed, mixed with 3 Tbs hot water
For 2 eggs (in some recipes, this amount can substitute for 1 large egg): 2 Tbs. ground flax seed, 1/4 cup hot water
You can either just let this sit for a while and then add to the recipe, or you can cook the flaxseed and water until gelled, let it cool and then if desired you can whip it to add more lift to your baked goods. You may need to add 1-2 Tbsp more water for the cooked and whipped version.
Another thing I've done when I want to substitute for 1 to 4 eggs is just add 1/4 cup or so of flaxseed meal to my recipe and increase the liquid a bit if needed. Flax seed contains quite a bit of oil, so you may be able to omit or reduce other oils in the recipe. It's pretty flexible, so you can play with the amounts without hurting your baked goods too much.
I do recommend using ground flax seed, or grinding it in a coffee grinder or spice mill to release the oils and the nice sticky compounds in the flaxseed that make it a good binder in baked goods.
If you're trying to make something like waffles and they are sticking, either grease your griddle better or try adding another tablespoon of flax seed and the corresponding amount of water.