Hi,

You can place for example registration form web part (~\CMSWebParts\Membership\RegistrationForm.ascx.cs) on you page template and modify it according your needs. You can add standard asp:FileUpload control to layout (.ascx file) of this web part and in code behind of this web part you can simply use example code from ~\CMSFormControls\UserPictureEdit.ascx.cs UpdateUserPicture method to save uploaded file together with user information into database.

Best Regards,
Miroslav Remias.