I have written an e-book, now how to market it?

I have written an e-book, complete with CAD drawings (plans) on how to build a baby cradle out of soild oak, cherry, or simlilar lumber.

Should I build my own site to try to sell them or is there other sites that I should use? Also what is the value of these plans, $1 each, $5 each, etc ???

Well, I'd say you have done the hard bit.....writing an ebook for a very specific niche market!

Getting it to the marketplace without a website is possible, but it wouldn't be my 1st option. If you build a site for it you can then target SE traffic. Shouldn't be too hard to get a nicely targeted flow of traffic.
The advantage of your own page is you can add Paypal payment buttons (for free) and capture customers email details, building yourself a future customer base. There is a bit of work in all this.....you also need to set up a delivery system for your ebook. This can be all done on "auto-pilot", so you never need to interact with your customers.

Another option is to list your new ebook at ClickBank, the largest and oldest online seller of digital products. You will need a sales page to do this. I take it your ebook is in PDF format? That is the most commonly accepted form for digital downloads.

A quality information product should sell for about 20 bucks. Say $19.95 for starters, and see how it goes.

Email me if you need any more help with all that.

Good luck!

I agree with the last user but 20.00 is a bit much. Do what he says but lower your price. You can always raise it if you start to sell and think that you have gone too little.