Some providers will provide free hosting, commonly under any one of three conditions:
1) you purchase something from them (eg. a domain)
2) you host it under their domain (YOURSITE.domain.com)
3) you allow advertising
Otherwise, it's hard to guarantee the reliability of a business. You can email them and see how well they respond, and also, provide yourself with "a way out." Pay by the month, so if something goes wrong, you don't lose everything. Money back guarantees are good, as is paying by a credit card (so you can request a chargeback from a bank).
I think you're off to a good start though. Realize your needs, and in your case: start small. There is always room to upgrade with any hosting provider. I've seen people pay for a top hosting plan when it really is not needed.