Battery Life
I'll start off with the most important thing that you should consider in a netbook - battery life. There are various types of battery packs that are used by netbook manufacturers in their respective machines. The most common of which is usually the 3-cell battery. This type of battery can give your 3-4 hours of solid usage before the battery dies out on you.
Some netbook manufacturers who want to offer the best netbook line opted to equip their machines with a 6-cell battery. Of course this will give you more than 4 hours of usage. The extent by which you can use a netbook with 6-cell battery depends how you are going to use the netbook.
Why is the battery important? Simply because netbooks are meant to be portable machines which you can use anytime. So having 5 or more hours of usage is certainly a must and should not require you to bring the netbookâs power adapter every time you bring your netbook. For me, it defeats the purpose of a netbook's portability.
Computing Power
Another equally important feature of a netbook - computing power, performance, speed or to be more technical about it - CPU. Before your choices was limited to the Intel Celeron Processor used by first generation netbooks. Then it became the Intel Atom CPU with two variants - N270 and N280. The Intel Atom N270 can give you a clock speed of around 1.6GHz while the Atom N280 can give you a slightly faster speed of 1.66GHz. In technical parlance the additional "6" is enough to make the N280 faster than the N270. If you value computing speed, you would definitely need to choose a netbook with the Intel Atom N280 CPU. But of course, this would come with a price, although not as high as you would expect. Currently, the Intel Atom N280 is being threatened by other "lightweight" CPU such as NVIDIA ION and CULV platform.
Display
Next thing you should consider of course is the size of the netbook's LCD, which is naturally also the size of its full form. The netbook craze started with the 7-inch display followed by the 9- and 10-inch models. Just remember the bigger the size of the LCD, the heavier the netbook becomes. So, if you would adhere to the netbook being a portable machine, then the smaller LCD is still your best choice. Although, you might find it hard to get a small netbook today since manufacturers have stopped manufacturing them. If you want a bigger screen such as the 9 or 10-inch netbooks, you're in luck. You'll definitely find one the suits your taste and needs. But wait, did we tell you that there are some netbooks with bigger screen already? Yes, there are and they are beginning to become the trend among netbook manufacturers.
Storage
Another important aspect of netbooks which you should look into when buying your first netbook is storage. Before, it was easier since you only have one choice - an SSD. But things have changed, netbook storage has become bigger and more spacious thanks to the deployment of HDD instead of SSD. Currently, the standard storage for most netbooks is around 160GB which is the same as most sub-standard regular notebooks. Of course, there are still some netbooks which use SSD for storage, and their SSDs have grown to as much as 16-32GB from as small as 4GB capacity. If you opt to have the HDD component, just remember that SSDs are more durable so your files and documents are secured even if your netbook suffered from bumps and drops. And of course netbooks with HDD for storage are heavier than netbooks with SSDs.