Hazel Eyes,Don't worry about being ripped off by ebook compiler software companies. All of them (at least the ones I've looked at) offer a demo version that you can use without cost. Nearly all of them offer a money back gaurantee. Be forwarned that some of them will ignore your request for a refund because they are not the ones that actually issue the refund. Case in point are programs that are purchased through a payment service called ClickBank.
The first thing you need to decide is what type of marketing you are most comfortable with. My preference is for viral marketing, which means that I encourage people to share the ebook with friends. The theory behind it is that the ebook has several free chapters that will help motivate a buyer to purchase the ebook.
A lot of the ebook compilers don't have the ability to unlock just a few pages and it is a matter of all or nothing.
Another thing to look at is the security system that they use. Keep in mind nothing is full proof from diligent hackers.
The two primary systems are that the ebook is completely locked (no free pages). For added protection an ebook can be set to periodically log onto a web site and verify that it is a legit copy. If it finds that it is not a legit copy it will relock the ebook. This feature is nice if you are concerned about giving a refund and want to prevent the user from continue use of the ebook.
The down side of this type of system is two-fold. First, there are currently no systems that relock a book and also allow selected chapters to be unlocked. Again, it is an all or nothing proposition. Second, there is a monthly fee associated with this type of service. Considering that less than on average there is less than a 2% chance of a refund it doesn't seem cost effective to me for ebooks that sell below $30-$40. If the ebook sells for hundreds (some do), then it would definitely be worth the additional $20 (on the average) cost of the service. (By the way there are such services that will do this for Activ e-Book compiled books.)
Activ e-Book uses the other approach. That is a number from 1 to 1000 is created based on the users computer system. That number is known as the Key Number. For each Key Number there is an unique Registration Number. The advantage of this system is that if the user shares the ebook with friends (and I hope they do) the friends will only be able to see the same free chapters that the buyer originally saw. There is less than a 1% chance that two friends will share the same Registration Number.
My suggestion is for you to download the different compilers and find the one that best suits your needs.