Reddit mentions of Relativity: The Special And The General Theory

The claim that "time is exactly like space" is not true. Time is treated as a dimension in Special Relativity (SR) and General Relativity (GR), but it is very different from the "usual" spatial dimensions. (It boils down to "distance" along the time direction being negative, but that statement doesn't really mean anything out of context.) The central idea of relativity is that while the entire four dimensional "thing" (spacetime) just is (is invariant), different observers will have different ideas about which way the time direction points; it turns out to be convenient for our description of nature to respect the natural "democratic" equivalence of all hypothetical observers.

I can point you to a couple of good resources:

This
is a very good, book about SR, and some "other stuff". It's pretty mathematical, and I wouldn't recommend it to someone who isn't totally comfortable with college level intro physics and calculus.

This
is the "standard" text for undergraduate SR; it's less demanding than the above, but uses mathematical language that won't translate immediately if you go on to study GR. (I have not read this myself.)

This is the book that I learned from; I thought it was pretty good.

This is Brian Greene's famous popularization of String Theory. It has chapters in the beginning on SR and Quantum Mechanics that I think are quite good.

This is Einstein's own popularization, only algebra required. All the examples that others use to explain SR pretty much come from here, and sometimes it's good to go right to the source.

This is a collection of the most important works leading up to and including relativity, from Galileo to Einstein, in case you'd like to take a look at the original paper (translated). The SR paper requires more of a conceptual physical background than a mathematical one; the same can't be said of the included GR paper.

I don't know what your background is--the first three options above are textbooks, and that's probably much more than you were hoping to get into. The last three are not; the book by Brian Greene and the collection (edited by Stephen Hawking) are interesting for other reasons besides relativity as well. For SR, though, another book by Greene might be a bit better: this.

I agree with rnally that in order to really get a hold of General Relatively you will need to know differential geometry (which in itself requires you to know calculus and differential forms, multivariable calculus, linear algebra, and maybe a bit of tensor analysis). However don't be discouraged, with just high school math you should be able to figure our Special Relativity. It brings me back memories of when I was a high school senior trying to figure out relativity myself and read Relativity: The Special and the General Theory by Albert Einstein. It's a neat little book and you should be able to get through the first half on special relativity (the highest math I saw were square roots), but again don't be discouraged when you hit the section on general relativity and if you understand everything up to that point you would have gone farther than I have when I was your age :). Best of luck! and good choice of major! (Majored in physics myself)

True, but even things explained simply are difficult for others to understand sometimes.

Good luck understanding relativity from reading Eisntein's book about it that he designed for the layman.

Here

Sometimes simply is simply not enough.