Some people think of SEEDS as a little wierd and health-foody, but when it comes down to it, they are old favorites ready for renewed interest: sesame, poppy, sunflower seeds, caraway, fennel, anise. Since it is impossible to generalize, let's look at them as the individiuals they are.
Sesame Seeds: I will talk about the unhulled variety called "natural" or "brown" in the stores where you would get them. The kind you buy at the supermarket in tiny packages for a minor fortune are hulled and bleached. See if you can vind the unhulled ones sold in bulk at a more reasonable price: not surprisingly, those hulls are loaded with essential minerals and B vitamins too.
Sesame Seeds have a delightful warm, deep brown flavour familiar to nearly everyone. Their size and shape make them easy to use on and in bread--to embellish a crust, usually all you need to do is roll the dough in the seeds as you shape it. For the very best flavour, toast them lightly beforehand in the oven or on the stovetop in a heavy pan (no oil required) As they toast, they pop, os use a deep pan like a Dutch oven on top of the stove if you don't want them all over the place. Stir for even toasting.
Much of the flavour of any bread comes from it's crust, so when bakers want bagels or rolls flavoured with sesame, onion, garlic, poppy, or caraway, they use plain dough and put the flavouring on the crust. It permeates! This is true with loaves as well as rolls, though since there is proportionately less crust, the effect is subtler. For a nicely sesame flavour, all that is necessary is seeds on the crust. Sesame enthusiasts who want more emphatic flavour may want to use fresh unrefined sesame oil when mixing up the bread dough.
You can also add toasted seeds to the dough, too, though it won't make the bread any lighter. Ground toasted seeds (I use my Bosch blender), add less flavour than you would expect, and definitely make a denser loaf; similarly with tahini, the flavourful sesame butter available in every natural foods store nowadays, often in raw, toasted, and in-between versions. When you buy sesame seeds, try to get them American Grown as they are cleaner and less likely to have pesticides used in the growing.
Poppy Seeds: Poppy seeds are usually more for sparkle than for flavour, though if used in sufficient quantity they certainly do have their own distinctive taste. With poppy seeds, very little makes a wonderful show: just 1 or 2 Tbsp. of a loaf's worth, will make an unmistakable poppy-seeded bread; a tablespoon sprinkled on a baking pan turns ordinary rolls into something special. Don't get white poppy seeds by accident--people will think it is sand or worse, mold. The black ones are called blue when you order them in bulk.
Sunflower Seeds: Sunflower seeds are so nutritious, so nutty, so easy to grow right at home. Why don't we love them more? I think it is because for years, when you visited any natural foods restaurant, you could count on finding the poor innocent seeds sprinkled in and on everything, often not having been substituted for more expensive "real" nuts; and there'd always be a few, raw and soggy, in the bottom of the bowl when you finished your salad.
Unlike sesame seeds, sunflower seeds do not have much natural antioxidant and so become rancid very quickly once the seed itself is broken. For this reason they are not practical to grind for butter or meal. Sort through the seeds you buy to remove any that are discoloured or moldy or whose shells have stuck to them--these make poor eating and may well be responsible for some of the Enemies of the Seed, Sunseeds are eminently nutritious, full of vitamins and minerals and fine quality protein.
Toasted Sunflower seeds are good in or on breads: about 1/4 cup in plenty for including in a loaf. They are at their nutiest when toasted; the flavour of the raw ones is milder and sweeter. Sunflower seeds are good not only with buckwheat but with oatmeal and with any dried fruit.
Caraway, Fennel, and Anise: These seeds are the three cousins and are sometimes confused one with another. Anise is the strongest of the lot, on the sweet side with it's licoricey fullness of flavour, Fennel is more herby (it provides the characteristic flavour of pepperoni sausage, and authentic Italian tomato sauces). With a bright pungent flavour in a lighter mood, fennel brings just the right sweet piquancy to make a Lemony-Fennel Bread extra special. Caraway is the most familiar of the three, putting in it's appearance in rye breads, bagels and in some English Sweet buns. Most of all though caraway has come to mean RYE--so much that if you make a whole wheat bread an put caraway in it, several people will assume it is rye; and conversely, very few will recognize rye bread without the seeds. I like to pulverize them in the blender before adding them in with the flour so I get the taste without getting any caught in my teeth when I eat it,
The three can be interchanged one for the other when someone has a strong antipathy to one, but the results will be a little different. How to say? Fennel is treble, caraway is tenor, and anise is the bass.
Cumin: Cumin is actually a member in this family too, more exotic perhaps, certainly less familiar in America, as a seed than as a ground spice that gives character to Mexican Foods. The whole seeds look very much like caraway, but cumin is not like anything else. Added to breadm, it has a roguish red chili flavour much loved by some. Use with caution --the first time, anyhow.