It depends on the size of your iTunes library. It's easier if you have a large enough iPod or external HD, but it's also possible with an ethernet cable and the network settings and a few other methods.
The iPod is by far the easier for larger libraries. If it's small enough, then you could just drag the whole lot and burn as a data dvd or cd (obviously the dvd would hold more). Even an 8gb library is only going to take a couple of dvds. So that it's up to you whether you can spare the time and dvds to do it that way. But once they're written, you can just load on your new laptop, drag and drop to itunes.
There's one problem there and that's with any songs or albums purchased through iTunes. The DRM won't let you burn them as an MP3. For those you'll have to burn as an audio cd and then import back into your new itunes.
Using the "back-up library" option will achieve the same results.
If you've an iPod which can handle your entire library, then it gets a bit easier. Even if not, you can set it up to use as an external device and use that to shift the music across rather than dvds.
Plug in the iPod, start up itunes and in Options select enable disk use. the iPod should now show up as a device on your laptop.
This isn't the whole story, but if you can load the entire library onto this, then it solves a lot of problems.
You'll need to get hold of some software for your new laptop that gets around all the funny stuff on the ipod that stops you just dragging the songs off it. There's plenty of free shareware out there, google SharePod (plenty of alternatives). This lets your new laptop treat the iPod as an external drive and you can then connect it to your new laptop and just drag the library into your new itunes. (note this software does not mess with, break or destroy your ipod and doesn't invalidate the warranty or anything, it's just a means of finding the hidden files).
The external hard drive one is also easy enough. Just find the itunes folder in your mymusic and copy the music onto the external drive. Plug into new laptop and copy into new iTunes.
The networking option is messy, so if any of these suit, try them first.