In Greece, the development of the teaching of Information Technology (IT) in schools has been greatly influenced by the rapid development of technology, making IT literacy a priority for all individuals. Consequently, the teaching of algorithms and programming, with the ulterior motive of teaching modeling as well as problem solving, has been greatly limited in Secondary Education. However, we strongly believe that algorithms and programming constitute an important intellectual tool and should be included in basic education. In any case, both the research literature findings, as well as, our own experience confirm the fact that novice programmers come up against many mental obstacles in their attempts to understand the functioning of programs or the construction of algorithms. In order to deal with these difficulties and successfully teach the elementary concepts of algorithms and programming, we have developed didactic scenarios, which are based on specially designed educational software. In conjunction with this, we are attempting to develop a program for the systematic training of those students who will become IT teachers in Secondary or Primary Education. The most significant findings of our research are summarized as follows: (a) The development of educational software and its experimental use in the teaching process allow us to formulate several general rules related to the specific didactic characteristics, which these environments should include. (b) Educational software is effective only when it is incorporated within the framework of the didactic scenarios that the teacher organizes and which are supported by the software. (c) Teachers do not spontaneously use educational software in the context of this rationale. Therefore, specific training is required so that they adopt and use such software in didactic scenarios.