how can i log on remotely to my pc at work?

What kind of machine do you have at work? If it's a Mac, and you're the only one using it, you can set it up with your iCloud account and use Back to My Mac to connect from home. That makes it very simple and easy.

If you can't do that (either because you can't upgrade it to Lion or it's a Windows machine), there's probably no way to do this directly. Doing so would require your work network to assign your work machine a static IP address that is accessible from the outside world, which they probably won't be thrilled about doing. So you'll need some kind of third-party software to do it for you through a third-party server that manages the connection. Some options are LogMeIn and GotoMeeting. I have no experience with either, so I can't recommend one specifically.

You really need to talk to your Work IT guy about doing this. It needs to be setup on the internet Router your workplace is using. They may also request you connect using a VPN connection (Vitrual Private Network).

There are a few steps to do this and it is best handled by someone locally that has the proper knowledge of networking and remote access.

If you have a Windows PC at work, then you most likely want:

Microsoft Remote Desktop Connection Mac OS X Client (free)

<http://www.microsoft.com/mac/products/remote-desktop/default.mspx ]]>

Applications -> Remote Desktop Connection

Computer: windows.pc.address

-OR-

Computer: windows.pc.address/console

Microsoft provides setup instructions on the web page where you download the RDC client.

There is also CoRD (Microsoft RDC Screen Sharing)

<http://www.macupdate.com/info.php/id/22770/cord>

The above assumes you are going to be using Microsoft Remote Desktop Connection

The other option is a VNC server on the PC and something like Chicken on the Mac

<http://www.macupdate.com/app/mac/36208/chicken>

There are other Mac VNC clients, such as JollysFastVNC, RealVNC, the builtin Mac OS X VNC client (which does not always play nice with 3rd party VNC servers).

Now if the work system is really a Mac, then just use the buildin Mac OS X Screen Sharing. From the client Mac use Finder -> Go -> Connect to server -> vnc://address.of.the.other.mac

The larger question might be whether you have to get through an office firewall or router. That might actually be the biggest problem, and if you have not already solved that problem, it might be something you need from your work IT group.