Game Training

There are some cool videos about chess theories, openings,etc available on this site.. Also u can refer youtube for the same. Playing puzzles is a great way of improving your tactical skills.. I would recommend you to study some openings(which u like) and practice it in your live games..

The best way to learn is by Playing and Playing innumerous games.. And more importantly analysing the finished game ( so that u can identify your blunders and try not to make them next time)

Good luck!

If you have the time to play 10-15 10 minute games per day, it is much better to play 2 30 or 60 minute games per side every day or even just 1 and analyze it afterwards.  

10 minutes per side is in most cases too fast for optimal improvement.

There's no concrete number. The quality of your practice, the consistency you do it in, etc. are all factors.