In reply to Ramblin dave:
The two biggest dangers on glaciers are seracs and crevasses.
You can see the former and make a reasoned decision as to whether or not to pass under them. Making this sort of judgement can only come with experience, and even experienced people can get caught out. Probably best as a beginner to avoid glaciers with seracs.
Crevasses are likely to be present on most glaciers. Where you can see them, known as a "dry" glacier, you can avoid falling into them, and bar making a slip, the risk is relatively low.
The real danger lies where you can't see them because they are covered by snow. This is a "wet" glacier, and much more dangerous. You should always cross a wet glacier roped, with prusik loops ready on the rope and ideally in a party of three or more. Two is better than being unroped, but it is very difficult for just one person to rescue another in the event of one breaking through into a crevasse, and being injured or unable to self assist with prusiks.
There are places where crevasses are more like to occur than other, and that is where the the ice is under tension as in a convex slope, less likely when in compression as in a concave slope, but they can occur anywhere and are potentially dangerous because you can't see them.
Sometimes you will see a big crevasse semi open on a wet glacier which is part bridged by snow. Crossing a snow bridge can be potentially dangerous, and should be done one at a time with the others belaying you and braced, and if it's a big one, anchored to their axes.
There is a lot to learn about glacier crossing and assessment of the risk and I would strongly advise you to go on an Alpine introductory course which covers crevasse rescue.