There are a lot of Latin curricula out there to choose from. Thanks to the help of my friend who is a college Latin professor, here are some recommendations.
The Best Middle School Curriculum
Many people today say they want their kids to learn Latin, but what they really mean is they want their kids to go through a fun workbook and show mom some cute phrases they learned. But if you really want to learn Latin, you have to work hard and get the morphology of the language down. If you are willing to do this, then First Form Latin from Memoria Press is the way to go.
First Form Latin by Cheryl Lowe is a serious morphology curriculum for the grammar stage of the Trivium. It is ideal for 6th and 7th graders (and maybe 8th), and is intended for those with no background knowledge of Latin. (There are Latin curricula out there for younger ages, but it is unnecessary to start Latin before middle school.) The workbooks are thorough, and they provide enough repetition and review to nail down morphology. This is not the most fun and exciting series, and students need discipline to do it. But they will learn Latin.
The First Form Latin textbook and workbook are both affordable. There is a whole host of resources to aid this series, including instructional DVDs. This series continues with Second, Third, and Fourth Form Latin. So one can use the entire series through high school. Third and Fourth Form focus more on Latin grammar, with Fourth Form keyed to Henle’s Latin: First Year.
This is probably the best curriculum available for middle school students. However, it is not perfect. Home school parents will probably need the instructional DVDs, and they unfortunately use ecclesiastical pronunciation instead of classical pronunciation (though there is a CD with classical pronunciation). The book also leaves out most macrons (which tell that a vowel is long). This makes the curriculum better suited for the teacher who already knows Latin. Additionally, the order of presentation is not ideal, as the book starts with verbs. But the order is better than most, and it is not difficult for the teacher to rearrange the order for class. One could easily begin with nouns (Units III and IV) before jumping into verbs (Units I, II, and V).
The Best High School and College Curriculum
The best option may be to use First Form and Second Form Latin for middle school and then transition to something more advanced for high school. The best book in this case would be Learn to Read Latin by Andrew Keller and Stephanie Russell. This is a college textbook, but it can be used in high school at a slower pace. It has a good order of presentation, and it provides good grammatical explanations. The paperback book and workbook together are under $100. This option is suited for a skilled Latin teacher.
Latin for Americans is another textbook that can be used at the high school level. This series is used in high school and colleges, and it provides a complete grammar and logic level course. One could start from scratch with this book in the 8th grade. The downside is that this series does not have the ideal order of presentation, and the book is a little pricey—just for Level One, the textbook is $100 and the workbook $24!
Latin Alive! Book One (and Book Two) by Karen Moore and Gaylan DuBose (around $25 each) is a popular middle school textbook/workbook. This series is a hybrid grammar/morphology approach and follows the series Latin for Children (A, B, & C) by Aaron Larsen and Christopher Perrin. This series is best avoided. The order of presentation is random and the books are riddled with errors. The grammatical explanations are incomplete, and the Latin used is often synthetic.
Wheelock’s Latin is the most famous Latin curriculum out there. This book has its advantages—it is only $12, there are tons of accompanying resources for the book, it has decent grammatical explanations, and it has good Latin sentences for translation. Unfortunately, the order of presentation is abysmal. If you know anything about language, the table of contents will give you a headache.
Latin for the New Millennium by Terence Tunberg and Milena Minkova uses a newer method of fusing ancient Latin with modern conversational Latin. This series is expensive ($75 just for the Level One textbook).
A Primer of Ecclesiastical Latin by John F. Collins is decent and only $20. However, this is primarily for ecclesiastical Latin and has a poor order of presentation.