
Quick Scan
Allow your Mac to use Screen Sharing in Sharing Prefs
Find the remote Mac in your Finder Window
Navigate the remote Mac through the Screen Sharing app that launches.
One Mac to Rule Them All: Control Other Macs on Your Network Remotely
Categories: Mastering the Mac
Do you have more than one Mac on your network? Are you lazy like me and don't want to get up and go over to that other Mac to use it? If you have permission, you can stay right there in your chair and control it from your Mac using Screen Sharing.
For me this works out great because I have a detached home office in my back yard that my Mac Pro lives in with everything hooked up to it. And being lazy like I am on most nights and some rainy days, I don't want to trek outside to go check my email or some file or website that I have stored on that Mac. So instead, I use Screen Sharing sitting on my couch with a creaky old PowerBook to control the Mac Pro. It's one-click easy as only Apple seems to make things and built into Leopard.
BTW, I know there are ways to work around sharing files, bookmarks, email accounts etc. between Macs, but Screen Sharing makes it not worth the hassle.
Another great use for Screen Sharing is to show someone how to do something on their Mac. You just take it over for a few minutes and demonstrate what you would like.
Setting up your Macs for Screen Sharing
It's pretty easy to do. Just go to System Preferences>Sharing and check the top box for Screen Sharing. You might as well check File Sharing too while you are there. Then just decide what permissions you want to assign in the area to the right and you are done! Now just repeat with any other Macs on your network you want to open to Screen Sharing.

Taking Control
So now when you are too lazy to get up to check that other Mac, just go to a Finder window and look in the side bar to the left for your other networked Macs to appear. Select one, then click the second button in the column, Share Screen… . Now the Screen Sharing app will launch and you'll see a version of the other Mac's display area appear within the window.

It takes a minute to get used to because you still have your Mac's menu bar at the top, then the Screen Sharing app's window with your other Mac's menu bar at the top of that. It looks a bit like your Menu bars and Docks are stacked. I often confuse the two.
So now when you move your cursor in this window, it will move your other Mac's cursor and when you use your keyboard while Screen Sharing is your current app, the commands will be directed to the remote Mac. So this means you can't just hit cmd-Q to quit Screen Sharing when using it. It will instead quit whatever app you are using remotely on the other Mac. You'll have to mouse up and use the menus on your Mac.
Sharing Tips
Odds are that your 2 Macs don't have the same size displays so sharing the screens can be awkward. You can choose between scaling the remote display to fit your Mac or keeping everything real size and having the view area kind of move around within your window. I choose to have everything slide around because Apple did a good job of moving the contents when your cursor gets close to the edge of the window. Hard to understand, but makes sense once you use it.
Copy and Paste
What do you do when you want to copy a bit of text from a document on your remote Mac to your current Mac? You can transfer the contents from your remote Mac to your current Mac and vice-versa, so the trick is to be in the app to copy from, hit Copy, then go to the Edit menu and choose Get Clipboard or Send Clipboard. That will just move the Clipboard contents from one Mac to the Other.
Can't I Drag Files From Screen to Screen?
No, the screens don't interact like that. For moving files, you are just better off loading the remote drive in your Finder window with the top button, Connect As… .
What About Really Remote Macs?
If you want to control the screen of someone farther away than the local network, try using iChat for screen sharing. For instance, if your mother-in-law the next state over needs help with her Mac, you can take over her screen and show her what to do. It's easy to do if you both are on iChat.
So now you know the lazy man's way of using a 2nd Mac that is just out of reach. A little prep in Sharing prefs and you should be good to go. Let us all know your tips and problems in the Comments section below!