This book is a step by step illustrated guide to planning and writing dissertations and theses for undergraduate and graduate science students. Topics covered include advice on writing each section of a thesis as well as general discussions on collecting and organizing references, keeping records, presenting data, interacting with a supervisor and avoiding academic misconduct. Recommendations about how to use word processors and other software packages effectively are included, as well as advice on the use of other resources. A concise summary of important points of English grammar is given, along with appendices listing frequently confused words and wordy phrases to avoid. Further appendices are provided, including one on SI units. The aim is to provide an easy-to-read guide that gives students practical advice about all aspects of writing a science thesis or dissertation, starting from writing a thesis plan and finishing with the viva and corrections to the thesis.