What are the advantages and disadvantages of various sugars/substitutes?
I can tell you a few things about artificial sweeteners!

Alot of artificial sweeteners look nothing like sugar (in terms of their chemical makeup) and have very different properties. Most are also sweeter than sugar (sometimes by a factor of hundreds) so in the packets, you will find that they come along with alot of other, inert ingredients. 

I found this link for you that lists various artificial sweeteners and their properties. Since most of them are nothing like sugar, you can't do certain things to them: such as heating to high temperatures or for example caramelizing. 

The link I gave you mentions which artificial sweeteners are safe for eg. baking and includes some natural subsitutes as well.

I'm not really familiar with their health aspects, but I found this link that discusses health issues with artificial sweeteners. 

Hope this is useful to you!