Topology-book for self study about physical meaning I self study physics, and I have come across some mathematics that are unknown to me. It has to do with helicity, linking numbers and other topological factors.

A friend of mine told me that this is called topology. I want to delve into this subject on a mathematics basis but with some physical meaning in it. So I wanted to know if there are any books that are easy to delve into and can teach me these topological factors (especially stuff that have to do with linking numbers) but also give some intuition and maybe some physics exercises (or more generally have some exercises that are not purely mathematical).

Also, except from books,do you know any other means to learn these topological factors (like web sites)?  

Thank you
I think Gauge Fields, Knots, and Gravity by Baez and Munian might be exactly what you're looking for. It is a very good text with plenty of illustrations that conveys good intuition about the mathematical and physical content. As per the title, the book discusses physical applications of knot theory, and the section starting on page 310 discusses linking numbers.
Metric spaces are basic to topological spaces.  There is a book of only 71 pages where one can learn what is a ''distance'' with a high degree of intuition.

Yu. A. Shreider, WHAT IS DISTANCE, The Chicago university press, 1974. ISBN 0-226-75498-7.