The Einstein Princeton lectures of 1921 may be a better starting point. He did there a great effort to present the material in a more pedagogical way, full of heuristic insights. Also, the formalism is somewhat closer to nowadays texts.
They are published in english under the title "The Principle of Relativity", and in german under "Grundzüge der Relativitätstheorie" (Springer). Both versions come with two interesting appendices Einstein wrote much later (in the early 50s I think), the first is about cosmology, the second is his last scientific paper ("Relativistische Theorie des nicht symmetrischen
Feldes" - Relativistic Theory of the Non-Symmetric Field). A LaTeX transcription of the english text of the lectures (without the appendices) is now available for free in the Gutenberg Project site.
It is a great text to grasp a little bit how was Einstein brilliant heuristic thinking, and it is not quite difficult to study, at least when compared to the 1916 Annalen der Physik paper.
NOTE: Not to be confused with another different book Einstein wrote, called "Relativity - The Special and the General Theory", which is merely a popular, non-mathematical introduction to Special Relativity (nice, of course, for readers with other interests - there you find the famous explanation of simultaneity with the train and the light flashes, for instance)