Courtesy- http://www.davidtheexpert.com/post.php?id=5

Like all of Apple’s software, Screen Sharing is incredibly simple, easy to use, and it works extremely well. Ever since I started using it, it hasn’t crashed a single time, whereas Chicken of the VNC crashed almost every time I opened it, and JolllysFastVNC crashed a couple times a day. Screen Sharing has exactly the features you need in a VNC client. It runs quickly and smoothly, it remembers your recent servers, and it can remember your passwords. What else can you ask for from a VNC client? You can even resize the viewing windows smoothly by dragging the corners, a task that is impossible with the other alternatives.

How to find and open Screen Sharing on your Mac

For sharing the mac first you login to Mac PC ( the PC you want to share), go to System Preference –> Sharing –> select Remote Management –> select these users

See the below screen shot

Mac Server-1

Mac Server-2

Mac Server-3

After done these settings in the the computer which you want to share, then go to client PC.
You can access Screen Sharing several ways, and I will tell you a couple of the simplest methods. Just don’t forget to create a shortcut in your Dock (or wherever) once you find it!

The easiest method is to use Safari. Just open up Safari and in the URL bar (where you would normally type a URL like http://www.davidtheexpert.com) type vnc:// instead of http://, followed by your VNC server’s IP address. For example, it should look something like this: vnc://
Screen Sharing will then show up in your Dock and you can drag it into the middle of your Dock to create a shortcut.
Safari VNC Screen Sharing

Another method is to simply find your CoreServices folder where the app is located. It is located here: /System/Library/CoreServices/Screen Sharing.app
My favorite method of accessing hard to reach folders is to go through Terminal (Applications Folder -> Utilities -> Terminall.app). Just open up Terminal and type: open /System/Library/CoreServices
That will open a Finder window where you will see Screen Sharing and you can open it or create an alias as you please.

Accessing your Recent Servers through Screen Sharing

Now that you have a shortcut to Screen Sharing, it’s a snap to get back to your last opened server! Every time you open Screen Sharing it will prompt you to enter your Server’s IP address. If you have already connected once, you can ignore this and instead click on the Connection menu in your menu bar, and select “Open Recent” from the drop down. Don’t forget to explore all these menu items because Screen Sharing has a lot of very handy features.