This is not as straightforward as you might assume. We'll just list a bunch of different things to keep in mind
1) People who get a book for free have much higher expectations than people who purchase a book. Be prepared for some brutal reviews
2) Very few people who get the book for free will be thankful. If having readers write in to say - thank you for your book - is something you expect, just get rid of that expectation.
Again, people who purchase a product are much more likely to be thankful
3) You cannot fight against human psychology. The most painful aspect of giving away books would be that people value what they pay for. For your 'free or cheap' book to be valued the same as an expensive book, it would have to be three times as good
If you think giving away books for free and/or helping people is a shortcut to getting recognition as an author, you're probably mistaken and it's a much longer route
People only value what they have to work for and/or they have to pay for
4) You need money to market your book, even if you are giving it away for free or very cheap. One big disadvantage of giving away things is that you aren't left with any revenues for marketing and sales
5) If you are giving away your books, you have no wiggle room for 'discounts'. A $5 book you can create a $2.99 sale or a $0.99 sale and drive a lot of attention. If your book is free, you have no way to make it more attractive
6) Free books will sometimes attract people not interested in the genre. These people can get it at no risk as it's free. Then they discover it's not their genre and will sometimes leave a bad review, hurting the book's future downloads
If making a book free, be absolutely sure to be 100% clear about what the book genre is and what the book genre is not. Otherwise your book will get sunk before it can take off
7) Getting people to download a free book is much easier than getting them to pay
It is around 20 times easier to get a free book download than to get a $0.99 book sale
It is around 10 times easier to get a $0.99 book sale than a $9.99 book sale
The 'Law of Unintended Consequences' dictates that if you are only giving away your book for free, you will never really learn the valuable marketing and sales skills that you learn from selling books for money
Even more dangerous, you might never attain the level of writing required to become a great writer. If you aren't getting readers to PAY for your book, how do you know it's a great book? Unfortunately, readers being willing to PAY for a book is often the only true test of it being a well written book
People value what they Pay For
If you really want to help people, you have to have them 'pay' for your book in some way. If they don't work hard for your book they will not value it, and might never even get around to reading it
We strongly recommend having some 'payment' to get the book
1) The obvious method is to charge a price between $0.99 and $2.99
2) Another method is to have them fill out a Questionnaire or do some 'good deed' in return for getting the book for free
3) You can also link getting the book free to something like charity or volunteering
People only value what they have to work for. People will be more likely to actually read your book and benefit from it, if they have to pay for it
You have to work with human nature, you cannot work against it
That brings us to a Painful and Inescapable Conclusion
If you want to become a very good writer you have to charge for your books
If you want readers to actually read your book, and value it, and take it seriously, you have to charge for your books
The more effort and 'payment' readers have to put towards acquiring your book, the more they will value it, and the more they will value you
It's a quirk of Human Nature that by 'helping people' and 'giving away all your books for free' you would actually not help them as they won't take your book seriously and not benefit from it. Additionally, they would not value you or your skills