Depends where you live. Europe (England?) uses SCART, here in America, TV's just have S-Video ports on them (look like the pic above). If your laptop and TV both have that port, get an S-Video cord from your local electronics retailer. Just plug the S-Video cord between your laptop and TV. You should get the laptop screen to come up on the TV. The S-Video cord ONLY CARRIES VIDEO INFORMATION, so you won't get sound out of it. The sound will come out of the laptop's speakers. If this isn't good enough, you can get a 3.5mm Minijack to RCA Stereo cable. It has the standard "headphone plug" on one end (plug into your laptop's headphone port) and the other end will have red and white (or red and black on some cords) connectors to hook the the red and white inputs on the TV.
If your TV has THESE inputs:
you'll need a S-Video-to-Composite adapter. These plug into the S-Video port on your laptop and have the yellow connector on it. You use a yellow Composite cord to go from PC to TV, and again, it will not have sound if you just use the one cord.
If your TV ONLY HAS THIS:
then you need a VCR or other device capable of taking the composite (yellow plug) output or S-Video output of your computer and converting it to a Cable feed to go to your TV (this is the kind of thing where the TV has to be tuned to Channel 3 or 4). Instead of the TV, plug the connection from the PC into the VCR's IN ports and then set the VCR to "Input", "Line", "Game", or whatever it calls the inputs. Tune the TV to channel 3 or 4 until you see the picture.
If you have the Red, Green, and Blue ports (called "Component" inputs), you'll have to have an S-Video-to-Component adapter. Again, it only carries video, but Component is capable of carrying HD (High Definition) video, so you'll get better quality using Component.
If you have the one labeled HDMI, you'll need either a DVI or HDMI port on your laptop. Only newer laptops tend to have HDMI ports, though some Macs had Mini-DVI ports, which you should be able to adapt to HDMI using a cord. You can get a cord that goes from DVI to HDMI or HDMI to DVI. HDMI DOES CARRY SOUND, so you WILL get sound through the TV with just the HDMI cord, HOWEVER, if you use a DVI output and convert it to HDMI, you WILL NOT GET SOUND because DVI does not output sound (HDMI does). Other than the sound, the two formats are interchangeable.