Everything I have read says that you do not need to soak lentils like you would beans. Unfortunately the last several times I have cooked lentils they have seemed a little chalky.
Should I be soaking my lentils before I cook them?
No, it's not necessary. You can do it, and if you'd soak them for about an hour, the cooking time will diminish strongly (half).
I'm not sure if this would affect the chalky taste. Which kind of lentils do you use?
You should probably be soaking your lentils, but it depends on what type. Soaking expands and softens the lentils, which may be the effect if you're going for something like dal (yellow lentils).
Lentils are high in phytates, which is an anti-nutritional - it's undigestible, and makes certain important minerals unabsorbable, like zinc, iron, calcium, and magnesium. Soaking (and throwing away the water!) helps to remove many of these phytates.
If you're getting a chalky taste, perhaps you haven't cooked them for long enough? They can be rather chalky or bitter if undercooked.
I would suggest that you try getting puy lentils. They are a French green lentil that have a great taste and texture like a bean . You do have to soak them and they will increase in size .They don't turn to mush like the split pea lentil.