What type of breadcrumbs do you recommend using? Also, how big should the little balls of croqueta batter be?

It's not a party in Brazil if you don't have "salgadinhos",or croquetes.My mom loves them,so I'm an expert...and as you notest a very modest one too!But kidding apart,about the crumbs:the finer the better cause if they're fine enough and your croquete dough is still warm,you don't even have to use egg whites or water to coat them and then they come out of the frying oil drier.Panko is great,I love it for nuggets but it may get a bit to much with the dough...you know?Too rich.The fine breadcrumbs on hot,hot oil will give you a crunchy flat crust in contrast with the soft interior...hummm,sooo good!I'm hungry now!About the size,for a cocktail party it should fit on a tea spoon.For tapas on a table spoon.And for drinks with friends or first course on a serving spoon.Usually croquetes are shaped into a cylinder.Ithe filling is cheese cubes(mozzarela or provolone) or hard boilled quail eggs,they're shaped into balls.And for shreded roasted chiken breast use a cone like shape to mock a chiken tie.You can also use hot dogs or olives...it's realy fun to try new fillings.Canned corn mixed in the dough is one of our favorites.My dough is pretty easy:for half a liter of milk (seasoned and salted-I'm not ashamed to say I use chicken broth cubes for flavor) add 1table spoon of butter and when it boils add at once half pound of flour and stir with an wooden spoon while it cooks,throw in an egg yolk and don't stop stirring till it forms a big ball and becomes loose from the pan.Let it coll a bit then when still warm take some dough and work it in your hands before filling it,and to incorporate something into the dough like the corn,do it at the "milk stage".Now I'm going to check out MariaTeresa's recipe.I'll try it at my mom's birthday,it looks delicious.

This recipe looks like it uses standard fine breadcrumbs -- you can make them yourself by food processing stale bread, or buy it in stores. For a flakier coating, you could also use panko breadcrumbs.

Because the croquetas are meant to be eaten as part of a tapas spread, I wouldn't roll them into much larger than 1" balls.