For creating citations in various formats (MLA, APA, and Turabian/Chicago being the big ones), try these online generators:
Son of Citation Machine - On the left click the format you'll need, then the type of source. Online sources are included. You can also type in the ISBN and choose either MLA or APA, and the website will find the pertinent information and generate a citation you can copy and paste.
EasyBib - This site has an option for subscribing, but you can get basic citations for free. You have more source options than Son of Citation, and it tells you right on the bottom of the screen which editions of each format it supports.
BibMe - Says it's faster than EasyBib. That may or not be the case, but it does say it's free. You can either have the site search for your pertinent information or you can input it yourself. If you sign up, it will generate and save your bibliography for you.
EasyBib seems to have the most types of sources included. Son of Citation Machine is the least pretty, but it's still functional. It's really a matter of choice. You can also Google citation generator to find more websites. You might also Google your particular format to double-check that your bibliography and foot-/endnotes look correct.