I was able to get a lot of information from the local library however if you are just starting to learn about physics (particularly quantum physics) I recommend starting with “A Brief History of Time”, “Mini Black Holes and Baby Universes” and “Grand Design” all by Stephan Hawkins. If you are more into the philosophical aspects of Quantum Mechanics particularly probability and time, I recommend reading “An Accidental Universe” by Alan Lightman which can be accompanied well with “The God Delusion” by Richard Dawkin. There are so many textbooks out there that offer some level of physics. I’ve even see High School level textbooks in either Higher Level Chemistry, Mathematics or most commonly Physics that offer a very (very very) superficial introduction to Theoretical Physics but trust me when I say it is better to build a strong foundation first before you dive into the harder theories although never be afraid to special further if you find a topic that interests you (I gather in your case this is string theory). I highly recommend researching the following topics by either searching Google books, pirate bay or sources from Wikipedia on the following topics:

Relativity
Special Relativity
Space-time singularity
Plank distance (and Plank Time)
M-Theory
Speed of light
Electromagnetism (and the Electromagnetic Spectrum)
parallel dimensions
Gravity (particularly Black Holes and Super Massive Black Holes)
Big Bang
Multiverse Theory
Worm Holes

and finally Bosonic String Theory vs. Super-string Theory

In actual fact, string theory is not really quantum mechanics as much as it is more Einsteinian Physics and really you should already have a strong fundamental in Newtonian Physics and Mathematics. Actually I have to apologize for before. Although knowing about Riemann Geometry and the Riemann Hypothesis helps greatly, this is advanced Graduate Mathematics and is not necessary when you are just starting. In terms of Mathematics, you really only need to be familiar with algebra and a bit of calculus, a lot of trigonometry and vectors and everything else can be researched as you go. If you want to learn a bit of Mathematical Physics, I highly recommend Maxwell’s Equations for electromagnetism.

Anyway these are all just broad topics in Relativity which you can think of as “big brother” of physics and deals with things that are very big. Quantum Physics on the other hand, deal with oscillations that affect everything but only can be recorded in particles that are very small. One of the first and founding experiments in Quantum Mechanics was the “Double Slit Experiment” which proved that a single photon passed through two distinct slits simultaneously. Other such analogy was “Schrodinger’s Cat” and “The endless coin toss experiment” which were both thought experiments that deal with probability rather than absolution. One of the reasons I cringe at the term parallel universe is how the layman may think of a parallel universe as a separate entity when really they are all the same of a higher space-time dimension (you will learn this in M-theory). The infinite coin toss thought experiment show this continuum by setting a condition. I have a coin a gun where I sit on a chair till the end of time. If I flip heads, I pull the trigger. If I flip tails I flip again. Theoretically if I flip heads, there is always some universe where I flipped tails. Since this can be repeated till the end of time, we must establish that there must be an infinite amount of parallel Universes but since we cannot substitute infinity to a Mathematical equation, we assume that the Universe is part of a higher Multiverse. You’ll find a lot of these thought experiments in Theoretical Physics (and even Theoretical Computer Science if you decide to move up a little). So long as you can prove your work Mathematically and with accordance with other well established principles such as Conceptual Physics or Experimental Physics, you can prove that your theories are possible (although not always plausible).

For Mathematics, if would help a great deal to revisit Calculus, Summation, Product and a lot of trigonometry. A good site to learn all of this and help build up your problem solving skills is artofproblemsolving.com although you can also read a lot of Mathematics textbooks. One of which titled “God Created the Integer” was actually written by Stephan Hawkins himself although you are going to need at least a few months to pace yourself. When I was learning a lot of these advanced Mathematical concepts, I found it became easier when I started to learn how to program. codeacademy.com teaches you programming for free and I highly recommend you learn at least two languages between ruby, python and javascript. This teaches you logic and often opens your eyes to new Mathematical tools and processes. I am a firm believer that the future of Mathematics is in computers so I find it to be easier to catch up now rather than later.

Anyway, I hope this helps a lot more than my previous post and I do apologize for my impotent comment prior. I do wish you all the best and if you have any comments or questions feel free to message me on Facebook at (https://www.facebook.com/julien.bongars.3).

Happy hunting!