As I continually say the checking the game guides with the Help Tab above the game screen is a good place to start to learn the basics of any game. Next a trip to the forums is always worth the time. The Zynga forums usually have a community created guides section where you can find a wealth of information contributed by other players.
Forum Links
Café World Forum
Support by Users for Users
Café World Guides
Tools
Farm Report This program runs on your PC and will let you know when your dishes are ready to serve. This tool also supports the crops for FarmVille and Farm Town. I use this excellent tool on a daily basis it works great.
Spreadsheets
Spread Sheet for Café World A contribution from LaughDonor, he has now placed the spreadsheets on his own web site.