Someone (you know who you are) asked me to repost a list of links I put together back in 2012 to help with outlining a NaNoWriMo novel. Here you go:
Planning, Scheming, and Plotting by Stephannie Beman -- Stephannie talks about her method of sketching out a nice, brief checklist to loosely organize her stories in advance of the writing.
Keith Cronin abstains from Roman numerals in his hybrid pantser-plotter approach to outlining, The Big O.
For those who prefer to write the classic synopsis as an outline -- there are one or two of you like that, yes? -- Charlotte Dillon has a fabulous page of info and links here.
If you'd like to organize your outline online, I recommend trying Hiveword, Mike Fleming's free online novel writing organizer, which I demo'd and reviewed here.
If you hate the idea of outlining at all, you may get some comfort (and ideas) from Crawford Kilian's post Writing Without an Outline.
Advice from a master: Effectively Outlining Your Plot by Lee Masterson
Alicia Rasley's classic article Outline Your Novel in Thirty Minutes asks all the right questions; you provide the answers.
For a very brief outline, test drive my one-page ten point novel concept outline template (the first page is the blank template; the second is filled in as an example.)
If you like Randy Ingermanson's Snowflake Method of outlining, you'll probably also love TextTree, a freeware written as a companion program for it.
TiddlyWiki is a free service that provides a reusable non-linear personal web notebook (LJ Cohen did a terrific virtual workshop a few years back on how to use TiddlyWiki to organize your novel.)
Try virtual whiteboarding with the free online service Trello, which I demo'd and reviewed here.
Juliette Wade's Sequence Outlining offers an event-driven method of outlining.
Writing.com has a Blank Novel Outline worksheet here.
And finally, a post I wrote that after five years remains the #1 most popular on PBW, my Novel Outlining 101.