I am a terrible speller, I need all the help I can get. So here is what I found out.

• Emacs uses an external spell checking program.
  • ispell is the original option.
  • aspell is newer and should be better.
• First install aspell
  • Windows: Grab the application installer and a dictionary here: http://aspell.net/win32/
    • If you don’t have admin rights, install somewhere other than Program files and tell the installer not to create a program group.
    • The dictionary will unzip to a TmpInstall folder. If the install croaks, look at TmpInstall\unix-install.sh to get an idea for manual install
  • Linux: Use your package manager.
• Add the following to your .emacs file:

  ;; Spellcheck
  (add-to-list 'exec-path "C:/Tools/Aspell/bin/") ;Adjust for your install path
  (setq ispell-program-name "aspell")
  (setq ispell-personal-dictionary "~/.ispell")
  (require 'ispell)

• Now start M-x flyspell-mode to get on the fly spell checking.
• To spell check a block of text, mark it and M-x ispell