Your goal should be that the reader can stop reading at any section, and still have learned something useful. You should make it easy for your reader to grasp the important things you have done without having to read all details. This style of writing is suitable for technical writing and is almost opposite to the style of writing used in fiction, e.g. thrillers, where the reader will not understand the story until the last few pages. The report should have the structure of a conference or journal paper in computer science. Here is an outline most papers follow.
Title Use a short and precise title which gives the reader an idea of the subject of the report.
Don't include background material here. The introduction section should set the context for the rest of the report. Give the motivation to why the treated subject is interesting. Explain where the work is heading at. Relate this briefly to other existing work.