Here's a code snippet that shows how you can get the information you're looking for.
TagLib.File tagFile = TagLib.File.Create(@"C:\MySong.mp3");
uint trackNumber = tagFile.Tag.Track;
string songTitle = tagFile.Tag.Title;
string artist = tagFile.Tag.AlbumArtists.FirstOrDefault();
string albumTitle = tagFile.Tag.Album;
uint year = tagFile.Tag.Year;
string genre = tagFile.Tag.Genres.FirstOrDefault();
MemoryStream ms = new MemoryStream(tagFile.Tag.Pictures[0].Data.Data);
System.Drawing.Image albumArt = System.Drawing.Image.FromStream(ms);