Code sample online aren't good for this. Hope this helps.
/*
Reference: Microsoft.SharePoint.dll
using Microsoft.SharePoint
Upload a file to a SharePoint document library. Many examples on the web seem to first
convert a filestream to a byte array (?). You can save yourself some trouble by just
passing in the stream.
Note: if you're confused about the arguments here, just browse to your document library
and look at the URL. If it's "http://mysite/Test/My Doc Lib", then the SiteUrl is as below
*/
private void UploadFileToSharePoint(string strInputFileName, string siteUrl, string docLibName)
{
string destUrl = siteUrl + "/" + docLibName;
string destFileUrl = destUrl + "/" + strInputFileName.Substring(strInputFileName.LastIndexOf("\\") + 1);
SPWeb site = new SPSite(destUrl).OpenWeb();
site.AllowUnsafeUpdates = true;
FileStream fileStream = File.Open(strInputFileName, FileMode.Open);
site.Files.Add(destFileUrl, fileStream, true/*overwrite*/);
fileStream.Close();
}
cf http://forums.asp.net/t/1164532.aspx.