As a new knitter, choosing between the needle options available to you may feel daunting. There are so many choices. Most people immediately think of two straight needle when they think of knitting, and rightfully so-it's iconic. But, I'm going to say something that may blow your mind, they are obsolete. If you observe knitters in practice, you'd be hard pressed to find someone utilizing these iconic tools.
Circs are better
So, what needles should you invest in as a new knitter? Circular needles [these needles can be identified by the cable that connects the needles]. Like traditional staight needles, circs allow you to work flat to create dishcloths and scarves, but when you're ready to graduate to more challenging projects, these needles are ready to grow with you. Circular needles allow you to knit wider flat garments, such as shawls and blankets, and, as the name implies, circular things, like hats and sweaters.
How to use them
When working flat on circs, just as you would with straight needles, you turn your work around and knit back the other way when you finish a row. When working in the round [or in a circle for hats and such], you will connect the two ends after your caston and never turn your work, continuing to work in only one direction.
Options, options, options
Circular needles are comprable in price to straight needles, and, just as their rigid counterparts, they are available in a variety of forms. You can find all of the same sizes and materials in circular needles as you can straight needles; choosing between them will ultimetly come down to your project and personal preference [ie. wood vs. metal, etc.].
I'm not saying that if you inherit a bunch of old straight needles, you should toss them [they're great to learn on, especially if they're free], but, if your are looking to start your collection and get the most out of your money and materials, then circular needles will take you further in the craft.