Is the only computer you have an iPad? That limits your options.
Now, how are the people you are sharing it with going to read it? They could read it in an email, or on a Kindle app, or...? Or just type it up in a Google Doc (online) and share the doc with them. The Google Doc app is free and they'd be able to read what you share with them that way without creating ebooks at all.
If you're wanting to publish bona fide ebooks, the easiest way to start (not the nicest but the easisest) is just type things up in Word and use a converter. There should be online "Word to Epub" converters, or to mobi, or whatever format necessary for their device.
The only app I know of that you could probably type in and produce ebooks is Scrivener, a publishing tool that does have an iOS app for $19.99.