Event viewer logs

http://www.eventid.net/search.asp

The above link is a source for searching and identifying resources (in the form of links to MS or other sites) for resolving a specific event id error.

You can also browse to the below link where you will find a link to a compressed Excel spreadsheet listing event id's for Windows 2000:

http://www.microsoft.com/windows2000/techinfo/messages/default.asp

Please remove any embedded spaces from either of the above two links while pasting it into your browser.

To answer your second question, as you will find there numerous software solution available to help you keep better track of (and more easily capture, filter, etc.) your event logs. Since some of these solutions can be pricey, they might be more appropriate if you have a large number of servers to to monitor. Unfortunately, Microsoft itself does not provide any tools beyond the basic Event Viewer to do this.
There are a couple of things you can do to at least simplify using the Event Viewer and keep you from having to visit multiple machines to view their logs.
In the NT4 Viewer, you can connect to other NT- based computers (I.E. NT 4 WS, Win2K Pro, probably Win XP Pro, as well the server versions of these OSes) to view their event logs. However you can still only view the logs of one machine at a time.
In Win2K, what I have done is create a cust MMC with the Event Viewers of all the computers which I monitor included. This at least alleviates having to connect to each computerin turn.
But the bottom line is, if you are only going to use the MS tools,you will have to manually go through the logs every day.
I realize, this answer doesn't really help you much, but it should at least give you an idea of what you're up against.