The best format for ebooks is in PDF format as the PDF ebook or document can be viewed in any operating system no matter it it Windows, Mac or Linux.

If you don't want to buy the PDF creator software, you can use a free and open source software called OpenOffice which is available for free download at openoffice.org.

You can write whatever topic you like in your ebook as long as it is legal to do so.

Once you've installed the OpenOffice software, open the OpenOffice writer and this is similar with Microsoft Word.

Just write your content or adding the images in it and when you are done, locate the red PDF icon at the toolbar.

To convert your OpenOffice writer document to a PDF document, just click once on that PDF icon and you get a PDF document in a few seconds.

I'm not saying this a perfect PDF document creator or converter but this is a good alternative to paid PDF creator or software.

You can buy one if you like and it is not really expensive.

With this OpenOffice Writer, you can create a special report ebook, product reviews, tutorials etc.

You can offer your PDF ebook for free download at your blog or website.

You can even submit that ebook to ebook sites that accept ebookk submissions.

To submit your ebook to these sites, just go to Google and search for 'submit ebook'.

You'll find a lot of sites that are looking for new ebooks to be added on their sites.

If your ebook is useful and helpful, the people will not delete it and will keep that ebook in their computers.

Don't forget to mention your blog or site URL in the ebook because some day they maybe go to your website via the link in the ebook.

Good luck and hope you can apply this knowledge soon.