Is there any rule to make words "female"?

Hello…
I saw that in dutch, to show that a word (like a profession or animal) are female, a sufix is added to the word. I learned some, like:
-e Chinees → Chinese
-es leraar → lerares
-in leeuw → leeuwin
-ster schrijver → schrifster

I wanted to know is there’s a rule for each sufix, and if there’s not, could you please me tell me an online dictionary where I could find the word with ther “females”?

Thank you all again

Good question. Do they?

I hadn’t thought about this issue.

However, according to this site:

… not really.

Any other suggestions?

Thanks for the site Harpagon…

Besides LingQ, I’m learning dutch from the following sites:

And I found these books for download, and they’re being very useful:
http://www.4shared.com/get/rAJ4XctD/teach_yourself_dutch_grammar.html

But some things are not very explained or they just don’t talk about them, then I go and ask here…
What about you? What resources do you use to learn dutch?

Well,

I think this is a good Dutch dictionary:

Sometimes I check these two websites:

http://www.dutchgrammar.com/ (you mentioned this site as well.)

Nothing out of the ordinary.

Good luck to you.

Yeah, I know BabLa Dictionaries… it’s a really good one.
Two I also look up words sometimes (mainly to check the pronunciation and articles) is http://nl.thefreedictionary.com/ and http://woordenlijst.org/.
One good source of audio, not only for dutch, is Acapela Box : create your text to speech messages.
Finally, for me http://www.telegraaf.nl/ is the best online newspaper, because its texts aren’t that big to read.

Thank you again