You want to store your image file in database o.k here you go:-
first take a FileUpload Control provide the Id of this control say fileUpload.
now take a button on button_Click write the following code:-
int length = fileUpload.PostedFile.ContentLength;
byte[] imgByte = new byte[length];
HttpPostedFile hpf = fileUpload.PostedFile;
hpf.InputStream.Read(imgByte, 0, length);
Now insert imgByte object into your database.
Remember datatype of your database column for Image must of type Image.