I found this lovely Speedball Textbook at a thrift shop a couple years ago. I'm particularly fond of the colour plates from the inside spread. Just lovely colours and of course lovely hand lettering styles. Look at those lovely ligatures in the Latin titling letters (the yellow one). Really gorgeous curves in the blackletter as well.
What's nice about this text book is that it gives you detailed instructions, almost like dance steps, on which nib or brush style to use and how to make the strokes.
You can still find this little book online at stores such as Amazon for pretty cheap.