What are good resources to self-teach mathematics? I am teaching myself mathematics using textbooks and I'm currently studying the UK a-level syllabus (I think in the USA this is equivalent to pre-college algebra & calculus). Two resources I have found invaluable for this are this website (http://math.stackexchange.com) and Wolfram Alpha (http://wolframalpha.com). I am very grateful that with those tools, I have managed to understand any questions/doubts I have had so far.
Can anyone recommended other valuable resources for the self-taught student of mathematics at this basic level?
I hope questions of this format are valid here?
Thanks!
 A: Yes, this site as well as wolfram|alpha are both excellent resources for teaching yourself math!
In addition, I would suggest looking at this site. It provides tons of great math videos, if you are like me and too lazy to read your book sometimes. :) KhanAcademy is also good, but I do prefer the latter. If you can afford it, perhaps you should consider getting into an online class? That way you get more resources and a professor to directly speak to. Not to mention, most math jobs require that you show some accreditation (e.g. a degree). Not exactly sure about your situation, but thought I would mention it. Best of luck!  
A: This is an old question, but this is for anyone else who might want this in the future.
For direct information about the a-level search TLmaths on YouTube, who has a playlist of just under 1000 videos covering the entire course.
For lots of free practice questions visit physics and maths tutor. 
I have recently found openstax for many great maths books, but is not specific to the a-level.
Professor Leonard on YouTube is great for any level of maths, and has great lectures.
I hope people find something here to help them learn.
