I've seen Schutz's new book
http://www.gravityfromthegroundup.org/ recommended as a nice introduction to special relativity and general relativity.
To quote his preface:
"This book has equations, but the equations use algebra and (a little) trigonometry,
not advanced university mathematics. What is required in place of advanced
mathematics is thought: readers are asked to reason carefully, to follow the links
between subjects. You will find that you can climb the ladder from gravity on the
Earth to gravity (and even anti-gravity) in the Universe if you go one step at a time,
making sure you place each foot securely and carefully on the rungs as you climb.
In return for putting in the thought that this book asks, you can get much further
than you might have expected in understanding gravity and its manifestations in
astronomy. School students and university undergraduates will find that this book
offers them an early avenue into subjects that are usually regarded as much too
advanced for them."
Not sure if it's more basic that what you may be hoping for but it seems to be pitched at a nice level covering some of the ideas and applications of gravitational physics. Check the website, you can have a glance at the preface, table of contents and some excerpts from his book and see if it's what your looking for.
Hope you find what you're looking for anyway!
