I'm Czech, so I know dumplings really well.

All of these recipes use "rough" flour - I wonder what it's called in English? Simply, here in the Czech Republic there are 3 kinds of wheat flour: the soft kind used for white pastry and desserts, the middle-rough type used in most recipes and the "rough" one used mostly for dumplings. It's softer than wholegrain.
My absolute favourite is
halušky, which is actually a Slovakian recipe.
It's very simple: grate raw potatoes (to get tiny "noodles", not the bigger ones), get rid of the juice if there's too much of it, add salt and mix with flour until it's compact dough. It's always very sticky, don't add too much flour to get rid of that! It would get too hard. You just want it to keep together. Make tiny dumplings and cook in salted water.
There are two ways of creating the dumplings: either you have the special tool I have - it's like a colander with big holes - mine is very similar to this one:
http://pabjan.files.wordpress.com/2006/08/30082006001.jpg - so if you have it, you put some dough into it, scrape it with wooden spoon above the boiling water and the dumplings create themselves. Well, not really, actually it's quite an ordeal... Or you put the dough on a wooden plate and cut off small pieces - dumplings - with a teaspoon.
Traditionally it's served with brynza (= Slovakian sheep cheese) and fried bacon. My family, and maybe even others, added fried onion to the mix. Or with sauerkraut. But you can experiment with the topping. I ate it with another kind of cheese and some sausages in Bratislava, and it was just as awesome as with brynza.
Potato dumplingsAnother favourite in my family. It's almost the same as halušky, except that first you cook the potatoes, than mash them and mix with flour and a bit of salt. I don't know the exact proprotions, but it usually differs with the different kinds of potatoes anyway. The dough should be consistent, but not
too firm (the same as with adding too much flour to halušky). Form balls (smaller are better - maybe 3 cm in diameter) and cook them in salted water for 10 - 12 min, or, until they come to the surface (general rule with dumplings - although sometimes they get stuck at the bottom).
The favourite topping in my family is: cut onion to tiny cubes and fry on grease or oil until golden. You can fry it together with pieces of sausage or other smoked meats.
You can also make filled potato dumplings - for example, filled with scrambled eggs. Yummy! These can be bigger, because there's a thinner layer of the dough.
Sweet cottage cheese dumplings with fruitI posted about them on my blog recently -
http://marmota-b.blog.cz/0807/tvarohove-knedliky-sweet-dumplings But here's the recipe anyway:
30 dkg flour
15 dkg cottage cheese (although I'm not sure if the Czech kind is exactly what's usually called cottage cheese in English... when you make it at home, you let milk curdle naturally, then put it into a kerchief over a bowl or something; the liquid part flows away and
tvaroh is what remains above after a day or so, without adding anything to it)
1/8 l milk
1 egg
5 dkg butter
salt
Make dough, roll out on floured surface, cut to squares approximately 6 x 6 cm. Fill with fruit (cherries, strawberries, apple halves or quarters...) and close carefully (eventually roll in your hands into balls). Cook in salted water as previously described.
Did you notice? These actually
aren't sweet. It's the topping that is.
There's also a leavened dough version of fruit potatoes (sometimes called
blbouny, but don't use that name very often, because it can also be an insult

). I've never tried it myself, but here's the recipe as I found it in an old handy cookbook of ours (the cottage cheese dumplings recipe also comes from there):
3/8 kg flour
1 1/2 dkg yeast
2 dcl milk
1 egg yolk
1/2 teaspoon salt
1/8 of the milk is used for preparing the yeast, together with sugar (2 teaspoons?) and 2 spoons of flour
Cook the dumplings for 5 - 8 min.
(This is absolutely off topic: when I was trying to get the terminology for cottage cheese, I stumbled upon this:
http://www.piens.lv/eproducts_curdsnacks.html If you ever visit Latvia, or even find it somewhere else, as they claim to export to the USA, try it! Those are the yummiest yummiest sweets under the sun. In Lithuania there's something similar sold under the name of Karvute, but there's also Karvute the toffee candy... both are wonderful, anyway.)
And then there are the Lithuanian
cepelinai. Those are really special, because you use potatoes
only for the dough. It's time consuming and
so tasty! And quite filling. We got the recipe from a lady in a bookstore in Trakai, so here I'm sending many many thanks to her, although she'll probably never read it...
Potatoes - 1/3 cooked, 2/3 raw. Eventually additional amyloid if there's not enough of it in the potatoes.
Salt the cooked potatoes slightly and mash them.
Grape the raw ones (just like for halušky), squeeze the juice out to a bowl and let it be until the amyloid settles at the bottom. We used a kerchief / teatowel / something like that for the squeezing. Pour out the juice carefully and put the amyloid back to the raw potatoes.
Mix the two potato portions together.
Filling: minced meat, 1 or 2 eggs, salt, onion cubes, spices according to your liking (as I remember, we put there thyme and it was really good, but you really have to make sure there are no places where there's too much of it.)
Or any other filling you'd like to use.
We also ate it with a sauce, but I don't remember how we made it... I only know there was onion and cream.
The potatoes are formed like this: make flat circles the size of your palm, put the filling in the middle and create round dumplings, a bit longer than thicker and a bit thinner at one end. They resemble zeppelins and that's where their name comes from.

Cook slowly for 20 - 30 min. !!!If you boil them hard, they'll come apart!!!