The field of cyber security is one that is growing rapidly. If you would like to get involved, then it is useful to experiment in real world circumstances, and this means that you will want to get some experience in doing cyber security work, hacking and cracking.
There is no substitute for actually working with the tools that are out there. That could mean hacking and cracking ‘white hat’ style, doing the hacking challenges that are out there – sites that are set up with the express idea of someone breaking in to them. Or it could mean getting out there and working on your own websites, or your own apps, and making a sandbox that you can use to do your own thing. There are lots of pre-made virtual machines on OSBoxes.org that you can download so that you can play with your favorite environments and make applications experiment with servers and do pentesting in a safe and legal way.
If you want to do wireless hacking or wardriving, then you will need a laptop that supports it, and to understand how to use linux, since a lot of the tools are made for linux rather than for windows. Laptop hacking can be a lot of fun, but you need to take care, and make sure that you stay on the right side of the law. If you ‘hack your friend’s wifi’ when they know you are trying, that’s one thing. If you hack the wifi in the office, and end up packet sniffing something sensitive that your boss doesn’t want people to see, then that could land you in hot water.
Not all laptops are ideal for hacking. You will need one with a wifi card or chipset that supports promiscuous mode wireless connections, and that will work with the tools you are aiming to use. It helps to have a decent amount of memory and perhaps even two wifi cards depending on what you are trying to do. A proper laptop could well be a better choice than a netbook. If your goal is to try and crack MD5 encrypted passwords, then a large hard drive for a dictionary attack and a fast processor to work through the attack will also be useful. Remember that it requires patience and some knowledge to do a good job, and you will need to always be learning to keep up with the latest skills.