457 -- Here are a few randomly selected examples of agency Rules of Practice: from EPA, the Department of Labor (see also DOL's Rules of Evidence), and OSHRC.
457-461 -- Here is the docket from a major FTC adjudication, this against Pom Wonderful for making misleading claims about the health benefits of pomegranate juice. Scrolling through, from the bottom up, gives a sense of what big-time agency adjudications are like: not so different from big-time commercial litigation in the courts. (But bear in mind that (a) not every formal adjudication looks like this and (b) fully litigated FTC adjudications are extraordinarily rare; the agency settles almost all its administrative cases.)
458 — A formal adjudication begins with a complaint. Here is an example, the complaint in the FTC’s Pom Wonderful proceeding. If you were the defendant, you would be disheartened to see the names of the ultimate decisionmakers on the complaint itself, would you not?
466 -- The current version of the FTC regulation upheld in National Petroleum Refiners Ass’n is here.
476 -- The Medical-Vocational Guidelines challenged in Heckler v. Campbell can be found here.
486 -- A rulemaking flowchart (the Reg Map). Here is a more user-friendly version, spread out over multiple pages. And here is another, denser, flow chart.
486 — Here are examples of informal rulemaking documents. You can, of course, find hundreds of others on regulations.gov.

• An Advance Notice of Proposed Rulemaking (ANPR) (financial crimes enforcement, anti-money laundering)

• A Notice of Proposed Rulemaking (NPRM) (arsenic drinking water standard)

• Another NPRM (Pedestrian Safety Enhancement Act rulemaking)

• A final rule (arsenic drinking water standard)

• Another final rule (Pedestrian Safety Enhancement Act)

• A Direct Final Rule (revision to safety standards for cribs and play yards)

509 — The Seidenfeld article cited in text, which is mainly an annotated table of analytic requirements for rulemaking.
524 — The fence-height instruction at issue in Hoctor can be found in section 3.2.5.3.1 of the USDA Animal Welfare Inspection Guide. If you did not have the link and the reference, could you find it?
562 — The casebook mentions that many agencies have their own rules about ex parte contacts in rulemaking. For example, the Department of Transportation has adopted a regulation, an order (see paragraph 11), and a lengthy guidance document
562 — The full ACUS recommendation on “Ex Parte” Communications in Informal Rulemaking
631 — An annotated sample FOIA request
633 — A random example of the denial of a FOIA request, and some examples of heavily redacted “grants”
657 -- Case studies of successful government transparency programs