While most schools (and many home schoolers as well) just cram facts down kids' throats and hope a sufficient education emerges, the editors and educators responsible for the Sonlight Curriculum take a less extreme, more well-reasoned approach. Education for them is not simply "knowing things," but rather absorbing an understanding of the world we live in as well as the tools leading from observation to true apprehension and interpretation. The Sonlight courses are built around hand-selected literature titles brought into a manageable and cohesive trajectory of study.
Originally Sonlight was intended to provide missionaries with full curriculum packages while they were in the field. Because the courses are not denominationally-specific, students are introduced to a variety of theological perspectives (from Reformed to Charismatic to traditional Baptist), especially in the upper grades. The creators of the program consistently emphasize the importance of exposing students to different and often obviously unchristian ideas, so the diversity extends beyond the realm of Christian thought. Content in the upper level material also tends to be more graphically violent and gritty than in the younger grades—though the younger grade titles are by no means fluff (not much fantasy or "light" reading here).
Sonlight provides primarily history-based curriculum for grades K-12. Each year is accompanied by an extensive teacher's manual providing a scope and sequence, lesson plans, supplemenary information, study questions, etc. to help navigate the extensive reading lists. Each year has a specific theme (usually an historical period) to which the bulk of the literature and history reading applies, while science, math and other subjects are treated separately. There is no "required" curriculum for math, though Horizons, Singapore, and Teaching Textbooks are all strongly encouraged.
A typical teacher's manual has 36 tabs, one for each week of a typical school year, containing detailed daily lesson plans. There are also appendices which include history, reader, and read-aloud study guides. Attempting to form a truly comprehensive educational program, the authors have even included information and checklists for gauging students' physical and character development. The study guides include supplementary information, maps and charts, comprehension and discussion questions, and vocabulary words.
There are two possible tracks for every year: the four-day track which allows you to get through a week's worth of work in 4 days per week, or the five-day track which takes 5 days a week but is more comprehensive and includes longer reading lists. Each weekly lesson plan is two-sided, with the four-day track on one side and the five-day on the other. One advantage of the four-day track is that it allows you to supplement with materials you find rather than having to rigidly adhere to Sonlight's schedule.
The goal of Sonlight is to allow students to see history as an interconnected narrative and to see how each cause has an effect. Students are to be taught to think creatively and logically and to assess everything in light of God's Word and a Christian worldview. The creators of the program believe homeschooling to be the best choice for Christians since it allows parents to direct course study as well as integrating biblical thought.
Each year is set up to form a logical progression, so younger students start at the beginning (ancient civilizations), progress to the Middle Ages and Renassaince and on to modern times, etc. Every three years or so the cycle begins over, covering each era in more depth than before, with a couple years devoted primarily to American history. While this pattern exists, it shouldn't be too difficult to transition into Sonlight from another curriculum, or out again when you're ready to move on.
Sonlight is an excellent concept and very well executed. The integration of all branches of learning within the overall context of a Christian worldview is one of the primary reasons many of us homeschool our children, and the creators of Sonlight have put incredible effort in devising a course that does just that. This attention to detail will lead some to feel the program is too structured. The teacher's manuals are highly specific—scheduling daily readings down to the page number—making it difficult to customize the content while using the manual, and equally tricky to use different editions. At the same time, with the amount of material covered each year the specificity of the teacher's manual can't really be avoided.
A minor concern is that students who come to equate great literature with "curriculum" will grow up lacking a desire to read on their own, at least to read beneficial books. The fact that kids in the Sonlight program will read a plethora of books entails a danger they will be turned off to them later on, though to be fair if you don't have them read great literature early on chances are they won't want to read anything at all when they get older. It's a double-edged sword and there isn't really a clear solution to the problem.
One of the most common complaints is that there is just too much reading, and that's probably true for most families. Also, in keeping with the theme of each year some of the titles selected don't seem particularly difficulty-appropriate. However, the breadth of each level leaves plenty of leeway for you to customize the reading lists to your own needs and abilities. Remember too that this is a fairly teacher-intensive program, requiring lots of parent-student discussion and planning, but also that this is ultimately a far more rewarding educational method for both the student and the teacher.