The entire notice, deposit and registration section of the statute can be found here.

§ 401. Notice of copyright: Visually perceptible copies

(a) General Provisions.— Whenever a work protected under this title is published in the United States or elsewhere by authority of the copyright owner, a notice of copyright as provided by this section may be placed on publicly distributed copies from which the work can be visually perceived, either directly or with the aid of a machine or device.

(b) Form of Notice.— If a notice appears on the copies, it shall consist of the following three elements:
(1) the symbol © (the letter C in a circle), or the word “Copyright”, or the abbreviation “Copr.”; and
(2) the year of first publication of the work; in the case of compilations, or derivative works incorporating previously published material, the year date of first publication of the compilation or derivative work is sufficient. The year date may be omitted where a pictorial, graphic, or sculptural work, with accompanying text matter, if any, is reproduced in or on greeting cards, postcards, stationery, jewelry, dolls, toys, or any useful articles; and
(3) the name of the owner of copyright in the work, or an abbreviation by which the name can be recognized, or a generally known alternative designation of the owner.

(c) Position of Notice.— The notice shall be affixed to the copies in such manner and location as to give reasonable notice of the claim of copyright. The Register of Copyrights shall prescribe by regulation, as examples, specific methods of affixation and positions of the notice on various types of works that will satisfy this requirement, but these specifications shall not be considered exhaustive.

(d) Evidentiary Weight of Notice.— If a notice of copyright in the form and position specified by this section appears on the published copy or copies to which a defendant in a copyright infringement suit had access, then no weight shall be given to such a defendant’s interposition of a defense based on innocent infringement in mitigation of actual or statutory damages, except as provided in the last sentence of section 504 (c)(2).

Comments: Since the U.S. joined the Berne Convention, formalities are largely voluntary and failure to comply does not risk forfeiture; but historically it has been otherwise.  Still, while a copyright notice is no longer required it is still imperative that one be used. Why? Primarily because of the evidentiary reasons listed in (d) above. In an environment like the Internet where it is a easy to copy someone else's work, you want to mitigate any potential defense of "innocent infringement." If the notice is prominently displayed then this argument is harder for a potential defendant to make. Although an "innocent infringement" defense is not a complete bar to recovery, it may reduce that actual amount of damages that a plaintiff gets. There is simply no good reason not to use a copyright notice for most (if not all) artifacts created for the web.

§ 408. Copyright registration in general

(a) Registration Permissive.— At any time during the subsistence of the first term of copyright in any published or unpublished work in which the copyright was secured before January 1, 1978, and during the subsistence of any copyright secured on or after that date, the owner of copyright or of any exclusive right in the work may obtain registration of the copyright claim by delivering to the Copyright Office the deposit specified by this section, together with the application and fee specified by sections 409 and 708. Such registration is not a condition of copyright protection.

Comments: You do not need to register a work with the U.S. Copyright Office to get the "bundle of rights." But registration, like notice, has it benefits. In the U.S. (with a few exceptions) a registration is required before an infringement suit may be brought. Another benefit of registration is that registration creates a presumption of validity, and validity of the copyright is often a defense that a defendant will assert. Registration simply makes it easier for a plaintiff to bring a cause of action against an infringer, allowing the potential recovery of up to $150,000 (and possibly attorney's fees) without having to establish monetary harm.

Comments: The registration process is relatively straightforward and inexpensive. Copies of the work will need to be deposited with the U.S. Copyright Office and the nature of the deposited copies will depend on the type of work (e.g. software requires a different type of deposit than a music video). In addition, the type of work will determine the type of form (e.g. a literary work will require a different form than the one required for a work of the visual arts) that must be used. In general, the registration should occur within three months publication (or before the infringing act) in order to get the aforementioned benefits. As a practical matter, registration should occur as soon as the work is published, otherwise the registration process is likely to be ignored.