For non-Chinese readers:
I'm a software engineer in Shanghai, China, and since I bought a Raspberry Pi, I spent some spare time on it and I'm glad to share something with Pi users all over the world, so this article has two languages: Chinese & English, and I try to translate the Chinese to English as accurately as possible, but, there might be some translation mistakes, so if you don't know what I mean in the article, just leave a comment, and I'll reply when I get an answer. Also welcome to contact me via Email.
Raspberry Pi是什么？
引用维基百科的一句话：
The Raspberry Pi is a credit card sized single-board computer developed in the UK by the Raspberry Pi Foundation with the intention of stimulating the teaching of basic computer science in schools.
简单地说，它就是一个基于ARM CPU的、信用卡那么大的迷你计算机。
In short, Pi is an ARM-based mini computer which has a credit card size.
在阅读本文之前，我建议你阅读另外一篇配置树莓派的文章，本文与它有一些联系。
Before reading this article, I recommend you to read another one on Pi configuration because this article has some connection with it.
为了能让树莓派摆脱每次使用都要插网线的麻烦，我最终还是决定为它配备一块USB无线网卡。在Google了一番之后，我发现很多树莓派用户都提到基于Ralink RT5370芯片的USB无线网卡，于是我购买了一个基于RT5370芯片的腾达(Tenda)W311MI迷你无线USB网卡（如下图所示），非常便宜的白菜价：只要￥30。
To get rid of the inconveniency of connecting a network cable to Raspberry Pi I decided to equip it with a wireless USB adapter. After Googling the Internet I found that many Pi users mention the wireless USB adapter based on Ralink RT5370 chipset, so I bought one too - the Tenda W311MI 150Mbps Wireless Mini USB Adapter(shown as below), which based on RT5370 and has a very low price: only $4.8 .