steamsteam-family-sharing
We have a number of games that have been bought with my Steam account and installed on my laptop. My child is now to get his own computer.
Preferrably he would have his own Steam account. If we want to install the games on his computer, is it possible to link accounts so they will be visible to him?
You cannot install a Steam game offline. It needs to connect to the Steam servers the very first time to confirm you own the game.
If you do not want to redownload the game, go online, click install, let it go as far as where it starts downloading, close Steam completely and copy the files from the SteamApps folder on another machine, then launch Steam again. However, this process still requires an internet connection on first play.
Unfortunately, Valve will not let you transfer games to a different account, unless they are gift purchases. As suggested in SqlACID's answer, you can create a separate account login for your son that still uses your Steam account login and password.
If you have Windows Vista, Windows 7 or Mac OSX you can additionally setup parental controls to disallow the launching of games that you don't want him to play.
If you want him to be able to launch games directly from Steam, I would suggest creating a new game category specifically for him and then add all the games you want him to have access to. To do this, right click a game and select Set Category..., then add a name. You can then select that category at the top of the games list. Here's a rudimentary example:
Best Answer
You can enable family sharing through 'Setting' -> 'Family' and check 'Authorize Library Sharing on this computer'. After that you can click on 'Manage other computers' to add computers.
Note that if you play a game on a shared library, that nobody else can play a game from that entire library. So, if you are playing a game, your child has to wait untill you close the game.
Also note that "Not all games support Family Library Sharing".
For more info that a look at the support page of steam.