How to get INNER JOIN result from two tables
Please try:

SELECT tf.font_id, tf.font_name, tcf.font_id, tc.charset_name, tcf.font_id, tcf.charset_id  
FROM table_fonts tf 
INNER JOIN table_charsets_by_font tcf ON tcf.font_id=tf.font_id
INNER JOIN table_charsets tc ON tc.charset_id=tcf.charset_id
WHERE tc.charset_name='latin';