C#教程
http://wenku.baidu.com/view/7e04df3467ec102de2bd895f.html
http://blog.csdn.net/hsg77/article/details/7302880
如何在.Net中访问MySQL数据库
http://www.microsoft.com/china/community/Column/63.mspx
TCP的:
http://www.cnblogs.com/longwu/archive/2011/08/25/2153636.html#
UDP的:
http://blog.csdn.net/andrew_wx/article/details/6671137
http://www.cnblogs.com/JimmyZhang/category/101698.html
C# Socket实现聊天通信
http://hi.baidu.com/jiang_yy_jiang/blog/item/3bf0f9fa75c7c913a9d31144.html