I believe you can find much of that information  in the SDK.

Can you be more specific? Have you tried to retrieve such info  before. I have never created a Custom WebPart before.

also have a look at the wss admin guide...
www.microsoft.com/.../stse\
09.mspx?mfr=true

I tried to create a simple WebPart "Hello World" using this document from Google

http://www.devx.com/dotnet/Article/17518
I have SharePoint installed on my machine from where I am developing the WebPart..

When I am at Setting the Output Path for Your Web Part Application..
Where it says
It's important to remember that you should set the Output Path property of the Web Part application to the bin folder of your SharePoint Portal site. If you're developing in a local environment, click on the Output Path field in the project's Property dialog and use the browse button to select the path. Typically, the output path will be

local_drive:\Inetpub\wwwroot\bin.

For me since I have SharePoint installed on the same box
Does it mean ---
C:\Program Files\SharePoint Portal Server\Bin

My project got created in

C:\Documents and Settings\reena.sardesai\My Documents\Visual Studio Projects\MyFirstWebPart
my dlls are in the bin folder in this path.
C:\Documents and Settings\reena.sardesai\My Documents\Visual Studio Projects\MyFirstWebPart\bin\Debug

Is the Web.config file for SharePoint in this path

C:\Program Files\Common Files\Microsoft Shared\web server extensions\60\CONFIG

Actually, it’s speaking about the bin directory for the web site  that sharepoint  has extended. It’s likely \inetpub\wwwroot\bin if you’ve not changed any settings and extended the default web site. Similarly, the web.config is in the \inetpub\wwwroot directory.

You might find another article helpful … http://www.devx.com/webdev/Article/29352 You may even want to look at the directory of articles at http://www.intranetjournal.com/sharepoint.