Hello Ramo,
In Moodle, the concept of "course" is different from the general concept of "lesson" or "programmed instruction" (which is probably what you are refering to).
A moodle course consists of a number of resources and activities, which can be displayed by the teacher week by week or all at once or hidden and then displayed at intervals.
A moodle lesson - which can be one of many "activities" inside a moodle course is similar to programmed instruction in that it takes the student along a pre-determined (by the teacher) path. Along this path, the student can be asked to read texts, answer questions of various types (only one question per page) and, according to his answers to those questions or his choices, can be taken along a variety of different "paths".
To sum up, a moodle course can contain a wide variety of activities and resources, but its "constructivist" philosophy is more geared to offering the student the choice of his own route than a "programmed instruction" philosophy where the route is pre-determined.
However, the "conditional activities" feature, especially in the new version 2.0 of Moodle, can be used to achieve a certain degree of constrained route, which might suit your needs.
Hope that helps,
Joseph
See also Pedagogy.