From my perspective (newbie, with a Windows main PC), there's 4 ways to do it, from simplest to install and barest functionality/comfort, to hardest to install but peachy once you've got it to run:
- get a text command line, via SSH and Putty on Windows
- do a kind-of Remote Desktop (Windows style) via a VNC server on the Pi, and a client on Windows. There's Ultra-, Tight-, True-, and plenty other VNCs for that, all with versions for windows, Linux (lots of flavours), and plenty other OSes, it is very standard. Be aware though that VNC does bitmaps, not vectors, so a lot more data needs to travel between the sever and client. Redraws are slowish and ugly.
- do a true Remote Desktop from Windows, using Windows RDP protocol, thanks to FreeNX server on the Linux machine. Vectorial, hence much faster and pleasant.
- take advantage of X11, which natively supports displaying one PC's stuff on another. Most Linuxes' user intefaces (lxde, gnome, KDE...) use X11. But Windows doesn't really have it, and getting it to run is a pain, the best solution I could find was actually install a Virtual Machine running Linux on my Windows PC, and do X11 remoting from there. Otherwise, there's a whole lot of hooplah involving Cygwin that's good for giving headaches, mainly.
Actually, a package and doc to enable good remoting to the Pi would be a very useful projects for those of us who do have a Windows PC.