Comment by FarmerPotato

Still good:

Lee Brodie:

1. Starting Forth. Somewhat dated (1979 FIG-Forth dialect)

2. Thinking Forth. Has software design lessons that go far beyond Forth.

These are free in pdf.

Elizabeth Rather, of Forth Inc:

3. Forth Programming Handbook. What I keep on my desk for Standard Forth.

4. Forth Application Techniques.

Dr. Ting has some good books. They're free pdfs now.

I also keep: Texas Instruments: TI Forth, by Leon Tietz, Leslie O'Hagan... and the vastly improved fbForth manual by Lee Stewart.