ACS Style is the most common citation style for chemists.
Try a reference manager. All reference managers have advantages and disadvantages. Mostly, it is a matter of preference. For more information about reference managers, go to
Probably not unless you plan on publishing your work publically (thesis or dissertation, journal article, etc). If you want to reuse images/figures from another author in your published work use the Copyright Clearance Center opens new window to find permission rules for various publishers.
You can also email a librarian for more help.