Chia seeds provide more omega-3s, calcium, phosphorus, and fibre than flaxseeds.
Get your chia seeds a little wet, and you'll see them turn into a kind of gel. This is the soluble fibre going to work.
You can easily make chia pudding, one of the most popular ways to eat the seeds, by mixing a quarter-cup of the seeds in one cup of liquid (almond milk and fruit juice are popular choices). Once the seeds have gelled up and the mixture is no longer watery, the "pudding" is ready to eat. This can take as little as 15 minutes, although chia pudding keeps well in the fridge for several days. Since chia doesn't have a ton of flavour on its own, feel free to add spices, chopped fruit, nuts, and any other toppings you'd like.
Dry chia seeds can also be added whole or ground to smoothies and juices, mixed into yoghurt or oats, or sprinkled on top of a salad. If you're adding the seeds to a drink or a "wet" dish like oatmeal, they'll swell up slightly while you eat, but they'll retain a slight crunch. And although these are some of the more common ways to eat chia, its mild flavour and compact size make it easy to slip a spoonful into pretty much anything—so experiment!