About viruses.. General info?

All of a sudden, I am fascinated by viruses. Does anyone have any book recommendations that might answer some of the following questions..

Did viruses evolve before or after bacteria?

Are there beneficial viruses? Like a virus that would "help" the host?

Can viruses be manufactured?

As far as biological classification goes, how are they classified? I know they aren't considered living.

etc...

About viruses.. General info?ktm

Did viruses evolve before or after bacteria?

We really don't know, but probably both. There are two schoools of thought on the origin of viruses. One suggests that viruses degenerated from cells, becoming totally dependent on their hosts. This is definitely true for many viruses, particularly DNA viruses. The other theory suggests that viruses, in particular RNA viruses, were the first form of life.

Are there beneficial viruses? Like a virus that would "help" the host?

Yes. There are viruses that infect fungi that live in plants around hotsprings. Without the viruses, the fungi and the plant die from the heat (Science. 2007 Jan 26;315(5811):513-5). There are probably many others, it's just that we often don't bother to study viruses unless they harm us or something we care about.

Can viruses be manufactured?

No, not really. There was a well publicized event where researchers were able to recreate a virus using short fragments of synthesized DNA, but this is very difficult and requires extensive knowledge. There is no way to generate a virus "from scratch" without knowing it's entire sequence.