Montessori Mom linked to this site this weekend and I am linking to it also in case you missed it. The Montessori Discovery School has an excellent, concise overview of the method, terminology, and goals for elementary level students.

If the next question is "Why do I care?" you might like to read the results of this study which showed Montessori trained children were head and shoulders ahead of their age-mates in both academic and social/emotional areas as compared to children in non-Montessori schools. Particularly noteworthy to relaxed homeschoolers was the comment that althought they were  "not regularly tested or graded, they did just as well in spelling, punctuation and grammar exams as those given conventional lessons."  This doesn’t have to be painful folks. ; )