I have found it very difficult.When they crow or lay an egg!Some breeds of roosters have a larger comb.And some hens have almost no comb.Sometimes the roosters will fight with each other.Hens have shorter legs(sometimes).You can google sexing chicks and that might be helpful.Some people are more observant than others.Someone else will answer with more positive answers,I hope.Posy Pet

Are these your first birds? What breed are they? In most breeds males will develop pointed sickle shaped feather on the saddle area of the back as well as in the tail.

I've got a section on sexing chicks on my chicken info site, here, scroll down to 'Sexing Chicks':

http://jackshenhouse.com/VSChickHensBroodiesChicks.htm

Also, the boys will have larger, redder combs. Roos are generally friendlier and come up to you more, and are the pretty bird that you like. What breed are they? As brendan said, look for the pointed hackle feathers at the base of the tail, also on their capes for the boys. Curved tail feathers are another sign of roos. If you post pics, we might be able to help more...

Velvet ~:>

Roosters are usually bigger and develop a comb before hens, at two months you should be noticing a bigger comb on the roosters and a small, pale one on the hens. For next year, use this trick in buying straight run. At three days old, the hens will have longer wing feathers than the roosters. Roosters will still have mostly fuzz on their wings and the hens will be developing feathers, about 3/4 inch long. This has worked well for me with the exception of getting one unplanned rooster. I also got one, unplanned rooster last year buying "sexed" hens. Same odds, works for me and they are straight run are less expensive.

My chicks are suspose to be 3 golden susex but they are white. The other 5 are black speckel susex.

We just bought 10 R.I R.and according to mollymaples's advice I think they are female. Thanks to everyone for your advice and the link.

This is totally unscientific but I find the hens have a gentler look in thir eyes.Their combs take longer to develop too.

I have a hen that I swear looks like a rooster. Actually 2 of them and if it were not for one of them laying eggs I would swear by it. On the same token there is one crowing that I would have sworn is a hen!! So my advise on that you don't want but I did find this info on the net that might help:

The two main methods of sexing chicks: feather sexing and vent sexing.
Feather Sexing
Feather sexing isn't hard, but it requires that the chickens be bred to show their sex in differences in the feathers as chicks. Male chickens in these breeds have longer wing pinfeathers than the females do, which makes them relatively easy to tell apart. Most chickens do not have these traits bred into them, and the chicks are identical to all but the skilled eye of the pro- chicken sexer.
Accurate Sexing Methods (Chickens)

Sex-Link Color
: A sex-linked chicken is one who's gender can be easily determined at hatching due to males and females being different colors. Without any genetic mutations, we can expect the following to be true:

Barred hen + non-barred rooster = Barred males and Non-Barred females
Gold hen + silver rooster = Silver males and Gold females
Barred rock hen + Rhode Island Red or New Hampshire Red rooster = Black with white spot on head male and solid black female (this is a Black Sex Link or Black Star)

Those are just a few examples of the various sex-linked combinations.

Vent Sexing
Vent sexing is performed by examining a day old chick's vent for the presence, or lack of, the formation of a male sex organ. The chick is held upside down to perform the examination. "Experts" are 95%+ accurate at this method. "Non professionals," after being taught the basics of vent sexing, can easily achieve an accuracy of 60-70%.

Watch them grow
The easiest but longest way to tell sex is to simply watch your chickens grow. In males, look for a larger comb, shinier, more pointed tail feathers (unless the breed is "hen feathered") and crowing. Females generally have smaller combs, tail feathers that are more rounded on the ends and, of course, they lay eggs.

That might not help but it was the best I could find...

There are no golden Sussex, they are red, light and speckled. The lights are white with black necks and tails. I guess the others are self explanatory, all Sussex have white shanks. Speckled chicks wont show the spangling until they feather.