That's weird, I don't know alot about that but are you sure it's not there? There's alot of formats to save it as, also if you don't know how you go File>Save As then where it says format click the down arrow and choose Jpeg, it's the 7th one down for me. If that doesn't work maybe reinstall?
Yeah, you can save to JPEG by selecting the Save For Web option in the menu, or the keyboard shortcut is holding down CRTL + ALT + SHIFT + S simultaneously.