Actually...
kaseida is the past form of kasegu, which means "to earn (money)"
chokin suru means "to save money" (usually in a back account)
...suru yoni (shite kudasai/ onegai shimasu) is a polite way of asking someone to do something.
So, your sentence means something like this:
"Please make sure to save up the money that you make."
Online dictionaries are your friends.
Here's a great English-Japanese one:
http://www.alc.co.jp
You enter the word in the form found in the frame on the left, then pick Japanese or English. This dictionary has a lot of examples, you will find it very helpful.
Another one:
http://www.aa.tufs.ac.jp/~jwb/wwwjdic.html
This dictionary has a few great features, one being that you can search with romaji, ie. kasegu instead of the same stuff in kana. They also have a Java applet that is much like the handwritten IME pad. It allows you to draw kanji with your pointer and search for their meaning and compounds.