3 Noob questions on animation and objects

I'm needing to do an animation, where an object is worn, then picked up and after some movement the object is placed back on the avatar. When it's pulled from the inventory, how is the object trained to know where it's worn, rather than having to select attach then select where to attach it each time? How do I detach and reattach the object to the avatar. And how do I get the avatar to drop and pickup the object?

I'm not sure I understand the sequence. First you wear the object, then pick it up?

The easy part of your question is that an object in your inventory will remember where it was last attached to your avatar. The first time you wear it use "attach to" in the menu. It will attach there every time it is worn until you change the attachment point.

You need to create a script and animations for your project. There is no way to script truly dropping and picking an object (attachments can only be detached - they stay in your inventory), but you can fake it by making the attached object invisible while the script rezzes a temporary copy of the object on the ground to be "picked up".

The Scripting Tips forum can help you figure this out, and also the LSL Wiki:

http://www.lslwiki.net/lslwiki/wakka.php?wakka=attachment