Most TVs will have HDMI and RCA component and composite jacks. Some TVs will also have a VGA port. Your laptop will have a VGA port. (If the laptop is fairly new, it may also have an HDMI port.)
Not all TVs will support an HDMI signal from a computer, so the VGA signal is often better. However, that limits you to SD (anything with HDCP will fail.)
Very few TVs ship with the HDMI or component cables. However, there are some vendors who do package the HDMI cable with their TV. Without knowing which exact model of TV and laptop, I can only make a few suggestions. I know that the TCP42ST30 (Plasma 42") doesn't have a VGA port.
Look at your laptop for any external monitor port. VGA ports are generally blue female ports with 15 holes (D-Sub). If your TV has a matching VGA port, get a standard VGA monitor cable.
If you have the VGA port on the laptop but not on the TV, you can try a converting from VGA to HDMI. (You may need a DVI to VGA adapter and either a DVI to HDMI cable or a DVI to HDMI adapter.) Note: this gives an analog signal (RGB format) to the TV. You'll also need to make sure that your VGA port is active (in the BIOS for some computers) and then set your computer to send the signal to the external monitor. It is best to turn off both the computer and the TV before connecting the two. Then turn on the TV and set it to the correct input before turning on the computer. (In Windows 7, I set the video signal for the external monitor by right clicking on the desktop and selecting Graphics Properties. Set the signal to the external monitor and click Apply. Then click OK (in the external monitor's screen).)
If this doesn't work, you need a VGA to component video converter. (Not a VGA to component video cable - those are for projectors that read the RGB signal.) See http://www.ramelectronics.net/audio-video/video-converters/vga-rgb-hv-to-component-video/c10000-c11200-c11215-p1.html
Some laptops come with an HDMI, mini-HDMI or a DisplayPort option. For the latter two, you will need the appropriate cable with that end and the HDMI connector on the other. Then connect the TV and the computer as described above. (Note: my TVs accept a computer signal at the HDMI port labeled HDMI/DVI. However, you need to make sure that your TV understands this signal. It isn't the same format as that from a set-top box. My laptop has VGA and HDMI out; the desktops have VGA, DVI and HDMI (on one).)
If you add a comment with the model of your TV and laptop, I'll be glad to give you more specific options to connect the TV and the computer.
I hope this helps.
(A DVI port is a digital video out option with ~21 pins and is usually white.)