A good first step to lowering sodium in your diet is staying away from processed foods, and making more things from scratch. Although it can be time consuming, with practice and patience it soon can take no time at all! If you are eating canned foods, be sure to read the Daily Value % on the label and rinse things such as canned beans to reduce sodium.
Probably the easiest way to start is to make sure you taste your food before adding any salt and learning to cook with herbs and spices for flavour instead. I love the complexity that herbs and spices can give food that only salt and pepper cannot.
Source: Government of Canada: Reducing Sodium at Home http://healthycanadians.gc.ca/eating-nutrition/healthy-eating-saine-alimentation/sodium/home-maison-eng.php