If you're going with a traditional two-year contract, you really need to select the right phone right away, because canceling your plan or choosing a new phone could cost you hundreds of dollars.
A lot of times phones cost a few hundred dollars more than what you pay the day you buy it. You might see a phone on sale for $200, but it might actually cost $450 to make. The wireless company charges you a cancellation fee to try to get that money back if you don't fulfill your contract. It might not seem fair, but it's how you end up paying $200 for a cutting edge phone instead of hundreds more.
You'll see phones on pre-paid options as low as $10. (There are some in the USA at Virgin Mobile.) These phones can generally call and text, and not really that much more. Perhaps set a timer to wake up in the morning. You're not going to be able to download thousands of apps like you could with an iPhone or Android-based phone. But many people don't need that, calls and texting is just fine for many, many people. You might be that kind of person.
As you explore this site, I encourage you to research your actual wants and needs before you sign up for a new contract. You shouldn't be paying $100 a month for a phone when a $25 a month pre-paid option would do you just fine based on what you want and need.
All that said, please remember that the wireless industry improves its service every day, month, and year because people bought cutting edge technology. The phone you can buy for $10 at a store now came from technology that originally costed thousands of dollars (yeah, I'm serious. Google it.) A plan thats $100 a month provides money to the wireless companies so they can built larger and faster networks.
If you're in charge of the budget or technology decisions in your family, you might want to consider purchasing a family plan. Whereas individual plans can end up costing $50 or more a month for a single phone, you can often add extra lines for about $10 a month per extra phone line. You still have to purchase the extra phones, and you're likely to pay more if you'd like to add unlimited texting on the additional phones. A family plan shares minutes, so as long as your total minutes used between all the phones doesn't go over your plan limit, you generally don't owe extra voice charges.
Prices do start to get more complicated if you'd want, say, two smartphones. You're like to pay a base plan fee for the family plan, then $30 per month for each phone for smartphone data, then addition charges if you'd like texting. If you're on a family plan and trying to save money, I'd suggest you only get smartphones for the people who actually need them, and get the rest of the family functional phones with text and picture messaging. That's just my personal suggestion.
Contract plans usually last two-years, and you pay a few hundred dollars if you cancel before the two years is up. They also usually require credit checks. That said, you can usually get a pretty cutting edge phone on a personal contract that might not yet be available in the prepaid market.
If you have good credit, and you're willing to commit two-years to one phone and one wireless company, choose carefully. It's a great opportunity, but it can also be a disaster. Personally, if you've never owned a cell phone, I'd recommend getting a pre-paid plan first and learn the system for a few months, then decide if you want to stay pre-paid or not. The great benefit of pre-paid is that if you're not happy with it, you just stop paying it and move on.
Pre-paid plans can be based on usage (you're charged for the minutes and texts you actually use) or for a flat pre-paid rate. (Virgin has pre-paid text plans starting at $25 a month, and Boost Mobile has an unlimited almost-everything plan for $50 a month, great for those who love to talk and text and don't want a contract.)
There are dozens of pre-paid and contract plans available, from many different providers. I encourage you to explore the options, then before you purchase, seriously look over your wants and needs and make sure the purchase decision you're going to make is something you'll still be happy with a few months from now.