There is no requirement to use a lawyer to file for bankruptcy. However, some people decide to hire one to help them get through the process.
Whether you're a good candidate for doing it yourself, depends on the complexity of your financial situation, and your willingness to take the time to learn the rules of bankruptcy. (If you're not the type of person that is willing to follow instructions carefully, then self-help is probably not for you.)
Your Financial Situation
If your debts consist only of unsecured credit card debt, you may well be able to file for bankruptcy on your own.
However, other factors to consider are the amount and type of property you own. If you own your home, have substantial retirement savings, or other substantial assets you may want to consult with a lawyer to make sure your property is not at risk.
A good way to approach the decision of whether to hire a lawyer is to buy (and read) Nolo's book How to File for Chapter 7 Bankruptcy. It will give you a good idea of what issues may arise when you file, and flags specific situations when a lawyer's help is called for. It will also give you a good idea of whether the filing process seems to complicated for you.
If your financial situation is simple, but you just don't want to deal with the forms, you might consider a using a Bankruptcy Petition Preparer to handle the form preparation.
Some lawyers may be willing to review your situation without taking on your entire case. If they see that your situation is very simple, some lawyers might even tell you that you can do it yourself.
Other Resources, Other Opinions
Lots of people have opinions on the topic of whether you should get a lawyer. Most lawyers... guess what... think you should always have a lawyer. But, seriously, they make some worthwhile points that are worth reading as you decide what to do.
The National Association of Consumer Bankruptcy Attorneys (NACBA) makes the case of why you should use an attorney and offers tips for those who cannot afford one.
The law firm of Moran Law Group, in addition to providing loads of useful free information about bankruptcy, also makes the case why you should get a lawyer and the US Courts site has this advice about filing without an attorney.
And Nolo has an article on Filing for Bankruptcy Without an Attorney
These are all worth reading.