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Are you saying you haven't drawn manga style eyes before? There are all sorts of ways to do it. You could have small black dots for the eyes, you could have totally realistic eyes, you could have big, bubbly eyes like your "typical" manga, or anything inbetween any of these. There's also the character's personality to consider; the eye shape often reflects this. Lazy characters will have sorta droopy eyes (see: Van from Gun X Sword), strict/pushy characters will have a flat edge for the top of their eyelashes (see: Kagami from Lucky Star), innocent/clueless characters will have round eyes, sly characters will have narrower/slits for eyes (see: Gin from Bleach)... Male eyes tend to be smaller than female eyes (see: Clannad).

However, you have to know that none of what I just said applies to all manga. Many series give the males the same sized eyes as females and give various styles of eyes to various characters even if that's not how it typically goes.

The only thing I can really say about the eyes is that they're a very important part of your style. The eyes and hair are the most distinguishable features between different manga (the bodies are usually all about the same - in good proportion - but sometimes they're distinctly different from the norm, like in Lucky Star or xxxHolic).
It's up to you to pick a style you like... can't really say much else about it. Some styles don't even put the white circles on the eye for shine (see: xxxHolic) and some styles just have a small black dot for the pupil (see: One Piece, Dragon Ball, Monster, Lupin the Third). Besides the shape, the way you colour it, whether or not you add shine, where you add shine, whether or not you have the black part of the eye, how big you have it, etc... lots of stuff to decide.

Chibis tend to have bigger eyes, but you're still free to use different eyes. You can just do a Google Image search for "chibi" if you want to see what's common. Or draw the eyes as you see them on Gaia avatars... our avatars are chibi.