you just need a b/g router if you want to use N speeds then you will need the router and buy a usb stick. For future notice the two main ways to plug adapters and add-ons to laptops is the PCMIA port and usb
There are for standards for wireless a/b/g/n which have faster rates of transfer as you go alphabetiacally higher n is the fastest a is the slowest. A wireless connection consist of two components a router and a computer. If the router supports the speeds b/g/n and the computer only does b/g then the connection is forced to use g speeds even though there is the potential from the router to be faster.
You have b/g built into your planned laptop so all you need to purchase is a g speed router, which has a max transfer speed of 120mbps which is more then enough for home use. If however you wanted to use n speeds which is around 300mbps then you would have to buy a router which supports it and a usb or pcmia card which supports it to plug into your laptop.
I use the belkin g+ router and it works well for me although it can overheat on occasion. but any router by a large company would be sufficient e.g. belkin, linksys, netgear