Christian Liberty Academy was one of the pioneers in home education. They have offered educational assistance through their home education program at extremely low cost because they view their role as one of ministry. They promote solid, Bible-based (Protestant) education and a very conservative (limited government) political philosophy.
You can enroll in their correspondence course or purchase materials separately. In their efforts to keep the cost of home education as affordable as possible, they publish many of their own books under the Christian Liberty Press (CLP) imprint.
An assortment of readers is available for all levels. Check their website to see all of your options; they differ significantly from one another. Of particular interest might be the Nature Reader series for grades one through five. These are reprints that have been reformatted from the original to make both print and pictures larger. However, they are not substitutes for basal readers but are useful as supplemental reading material.
CLP has put together inexpensive reading kits for both beginning and remedial instruction that incorporate their books along with others. CLP's set of beginning phonetic readers are an excellent tool that might be used along with other phonics programs. Also, check out Noah Webster's Reading Handbook, a self-contained, uncluttered approach for teaching phonics. (Note that I review CLP's complete kindergarten program here.)
CLP publishes their own Applications of Grammar courses for junior and senior high.
The CLP Handwriting series for kindergarten through fourth grade features the traditional ball and stick/Palmer method. While they are not visually exciting and colorful, they do the job of teaching handwriting.
The Building Spelling Skills series (for grades one through eight) takes a rule-oriented approach to teaching spelling, building first upon phonetic skills. Their sixth grade spelling book is particularly useful for reinforcing spelling rules.
The history books are an eclectic assortment of reprints and new books that can be used at various levels from first through eighth or ninth grade. Some of the readers are also quite useful for history coverage. Some of their historical biographies of Robert E. Lee, Stonewall Jackson, and others might be of interest. Streams of Civilization deserves special mention here as a unique and interestingly-written, two-volume history text for junior and senior high although there is quite a jump from one level to the next.
CLP science worktexts for kindergarten through third grade seem to be a real contrast to the general Christian Liberty approach because they are very hands-on, experiment-oriented with plenty of thought-provoking questions.
Bible courses are available for preschool through eighth grade. CLP’s Stories from God's Word Series: Bible Nuggets and Bible Treasures, are excellent options for preschool through second grade level. The higher levels of the Studying God's Word series (books E-H) are excellent. The Studying God's Word series is suggested up through seventh grade, but these books are so good that I would recommend them even to older students, perhaps starting with books F, G, or H.
Teachers manuals are very brief primarily serving as answer keys. They are very inexpensive and are essential for most courses. That also means that lesson preparation is minimal to non-existent. Ease of use and low cost make some of CLP’s resources hard to beat.