I have questions in making textures
Can I draw with a mouse?
Can drawing with a mouse produce as good detail as the flyingmonk's work?
Can someone give me a link to a good tutorial/s?
You can certainly draw with a mouse, however it'll be very difficult. Theoretically, you could match the work of some of the top artists on here, however it'd take a long time of dedication and skill with creating art (just as anyone else creating high-quality art needs, regardless of what tools you use).
There's a variety of tutorials pertaining to the creation of art, which I'll link here:
Flyingmonk does not use it, all his stuf is C/P from real pics/other works. Still, you can draw with mouse. http://imgur.com/a/PiECO was done with mouse by me. GL!