I am planning on submitting a book manuscript to publishers.  Is it permissible to place a copyright notice on the manuscript?

You are permitted to place the symbol © on your manuscript with your name and date of creation.  A copyright exists from the moment a copyrightable work is created. Registration is not a prerequisite for the symbol. If you decide to register,  “[t]he effective date of a copyright registration is the day on which an application, deposit, and fee … have all been received in the Copyright Office,” Section 410(d) of the Copyright Act. 

Note that you can also register your manuscript for a certificate of copyright.  Section 408(e) of the Copyright Act provides that “Registration for the first published edition of a work previously registered in unpublished form may be made even though the work as published is substantially the same as the unpublished version.”