//Quick Reference for Web part properties
[WebBrowsable(true),
Category("Miscellaneous"),
Personalizable(PersonalizationScope.Shared),
WebDisplayName("Enter some text")]
public string CustomTextProp { get; set; }

http://blog.concurrency.com/sharepoint/create-a-custom-web-part-for-sharepoint-2010/

Great tutorial for getting started with SharePoint custom web parts

SharePoint 2010 Developing Custom Web Part

web, user

C#