General rule of thumb is not to sign up for yearly web hosting plans. Instead, get monthly plan where you can unsubscribe from on second month when you are not happy with service. That is, if you ended up with an unreliable web hosting company in first place.
Here is a simple guide that can be easily applied to typical web sites:
Expect a small website to take up 10 and 100 MB. Considering that you may want to expand your website in near future, it is advisable to get a web hosting plan with ample web space.
Make sure that you know your needs before you start looking for your web host. Not every web hosting plan can be upgraded or customised. More than often, webmasters do not get features they need and are not able to customise their web hosting features.
Data transfer per month are typically referred to as bandwidth. It is amount of data transfer that occurs between your website and visitors. A small or medium web site will consume between 1 and 5GB of data transfer per month. Larger, commercial or popular websites often consume more than 5GB of monthly data transfer and sometimes, exceeding 100GB of monthly data transfer.