Figuring out exactly "what to write, when" when you are launching a
startup that needs to raise money, can be very challenging. When I
started my first company, I slaved over the complete, prose, version of
our business plan, but neglected the powerpoint slides!

Here is what I recommend for the emerging startup
1) Elevator pitch (see my previous post)
2) 1 paragraph summary of the business (for email)
3) 1 page exec summary (for introductions to angels, VC's, and for
investor beauty pageants) - ONE PAGE ONLY!
4) 3-5 page executive summary (for anyone who is potentially a serious
investor - they will ask for this)
5) A 15 slide powerpoint presentation (NO MORE THAN 15 slides).

Guy Kawasaki says, take the oldest person in the room, divide their age
by 2, and that is the SMALLEST font size you should use. For the
mathematically challenged, if there are mature people in the room (i.e.
people with money) who are, say, 60, then the smallest font size you
should is 30 points. This is great advice, now, go back to your latest
powerpoint and check that font size!

It is MUCH harder to write a short summary, than a long summary, which
is why I recommend these items in the order that I do - to get a really
good elevator pitch, you really have to know your story.

Once you have items 1-5 done, then you can "write" the novel version
(although still, no more than 25 pages of prose), of your business plan.
Of course, by the time you have 1-5 done, you've already done all the
thinking and all the modeling and spreadsheet work to really understand
your business - so the writing / expansion will be much easier. In my
experience, the only person who will read this is the associate at a
venture capital firm which is really interested in your business - and
then only in due diligence. Get 1-5 done and get on the road raising
money, and you'll have plenty of time on the plane to write the long
version!

As a note, if you're new to raising investor capital for a startup,
visit this earlier post.

This is a presentation I gave at the request of the Fund of Funds called
"Designing the Perfect Investor" (tm) which walks through a lot of the
elements of raising money. It is < 1 hour and is designed to be primer
on fund raising and includes the video/audio of the presentation as well
as the direct view of the slides.