Module development and code questions

from this doc page:
http://drupaldocs.org/api/head/function/hook_nodeapi
I am trying to find out when the node actually gets written into the db. ( i need the value of 'nid' ) Is it saved during the 'fields' operation, or during the 'insert' operation? when can i find out the value of the freshly inserted node id, to use as a key in my auxillary node data table?

Hi, I've just got Eclipse going. I've downloaded what I think is the HEAD, but it's not entirely clear.

The top of the changelog file says:
drupal x.x.x, xxxx-xx-xx (development version)

Does that mean this is the HEAD version?

How do I make the menu for SimpleNews settings invsibile to users?

Sorry about my poor english...

I am trying to add a custom field to a page node. I know that it is possible to define custom nodes using flexinode, but I do not want to use this module. I only need one more field in the default node.

I think that I would create or extend de database in order to store this field, and I would need to extend the page module.

It is possible?

Thanks in advance

Say that I want to create user groups where each class is its own user group. And I each want them to view their own data but not somebody elses. How would I accomplish that? I want each class to read its own announcements, its own forum data, etc etc. Is there something I can do with taxonomy to make that happen? I don't really want to have to build custom modules for everything or hack a bunch of modules to get this accomplished.

Thanks!

Jay

I have a page on my site where I show nodes of a certain category and right now they're in order of date. Is there a way to make them in order of their weight and add a weight (like with blocks) to each node? Does that make sense?