The form is available on the IRS website at this link. Data may be filled-in on the form and saved, so it doesn't have to be re-entered on each request.
A taxpayer operating a business under Schedule C, E or similar is entitled to apply for an additional EIN by applying with the SS-4 form by fax or mail. Regardless of how many Schedules C, E and similar, a taxpayer may only have one additional EIN, which is directly associated with (and provided to counter-parties instead of) their social security number.
An EIN may also be attained instantly by filling out the application at this IRS link.
FYI, it's not a terrible idea to keep a filled-out, signed SS-4 on file even if you apply on-line (there's a place on the form to record the number) - you never know when the IRS would demand paperwork (I'm a big believer in bulletproof paperwork).
Hope this helps,