What is the maximum length of an url?
What is max number of Query Arguments supported in the GET Request and in total how long can this GET request be?
Similarly for POST Requests.
Finally, Good resources for Base64Encoding and Multi-part Form Post requests would be great.
AFAIK this isn't defined. I think IE6 had a max of 2048 characters for a GET request length.
You might want to focus on what it is you're trying to achieve after learning this. As Martin points out, this isn't really defined. Why do you want to know this, anyway?