There are many possible tools that could be used by people who are learning stand up comedy.
One of the tools is as close as your keyboard - video sharing sites.
The most popular one would be YouTube.
It is very easy to use and is full of comedy routines for your to study - heck anyone can post their videos on YouTube whether they are funny or not.
And you will most likely have fun while you are doing it.
You can start with well known comics that have videos on YouTube or you could try a comedy genre.
You can find a huge list of comedy genres and the comics that fit into each genre by using Wikipedia an search for "comedy genres".
The list is quite impressive.
If you are not sure about the specific genre that you want to work in, watch videos from several genres and see what "feels right" and fits your style.
Next, when you have several videos that you like and fit your style, transcribe that content of each video.
As you read through each gag, you will realize that many times the funny part is mostly in the delivery and not the actual words.
After you read the material, watch the video and hone in on the comic's delivery.
This will give you an all around view of the comic and the jokes and stories he/she is telling.
While you are viewing the videos, don't just listen and laugh.
Really study the video as a whole.
There are actually metrics that can be applied to a comedy routine.
Here is a list of some of the top things to watch for.
As you keep studying, you might come up with some of your own.
This is not to say that comedy is a formula, but there are some things that make one routine better than another.