All of this is cover in a simple search of the forum.
Here is the short answer..
Dye sub is best....there is no hand (you cant feel the ink) great colors (only works on polyester white or light colored shirts)
Pigment would be next best...using a heat transfer paper, good colors, works on light and dark shirts..just with different papers. Works on 100% cotton and cotton/poly blends. Dark colors have a heavy hand and light colors you can feel the print but its not bad at all.
Dye ink....not recommended for anything getting wet or washed, etc. (the simple answer is ...dont pick this one). This is usually just for typical office printing.
For more detailed info you can search the forum and read for yourself.
You will learn a lot more reading the info your self then having someone hand you it.