Hey, I am just getting into biking more seriously. I really want to learn the mechanics of a bike and how it works, but I don't have any tools. Could you guys link me to a good set of tools and possibly a good book or something that could help me out?

Secondly, I just got a new bike and me left crank fell off quite quickly. Within a week. The crank got replaced and I was told that after a few rides I should check to see if the 8mm hex bolts were tight to prevent this from happening again, but apparently I need a special allen key to do so (a torque wrench?). Help me out with this? Sorry, like I said I'm new to this stuff and I hate not knowing anything about the subject. I'm lost when it comes to bike mechanics, I don't want to rely on my LBS to do everything for me.