Here's a recent series that just got a new instalment today: It introduces template basics in a nicely explained and accessible way suitable for a gentle introduction, and then going on to progressively help the reader develop stronger template muscles.
C++ Templates series
And today: Template Specialization
From the Introduction:
Templates are a very powerful -- but often very confusing -- mechanism within C++. However, approached in stages, templates can be readily understood (despite their heinous syntax).
The aim of this series of articles is to guide beginners through the syntax and semantics of the foundation concepts in C++ template programming.