I have been using the Opera browser for ten years or so and still find it to be the best there is. Opera has had all the best features, such as mouse gestures and tabbed browsing, long before Firefox or Internet Explorer. What's more, they are built in so you don't even need to download dozens of plugins to make it usable in the first place. I'm also using Opera Mini in my cellphone.
That being said, I think Firefox is a great browser too. I couldn't, for example, do any web development without the Firebug plugin anymore. Adblock Plus is an absolutely crucial plugin for any Firefox user as it blocks the ads -- netbooks usually don't have screen space to waste, nor do they like heavy, flashy web pages.
So, my point? There are alternatives to Internet Explorer, and as a netbook owner you should definitely try them out and see if they perform better than IE. Lifehacker's blog post from a couple of months ago compares the browsers. In the end, IE gets the lowest score of them all. They were the first to admit that the measurements are not very scientific or too accurate but I do think their results bear at least some significance.
If I were you I would now start using Opera because a) it is, in my opinion, the best and b) because I will post some Opera tips later.