Since you got the free trial of Lightroom, learn as much about it as you can so you can decide whether you want to stick with it. There are plenty of free tutorials online, some great books, and then there are organized for-pay tutorial services such as Lynda.com and KelbyTraining.com that have some great stuff. But, in the meantime, adobe TV has good Lightroom training material, and there are three authors of good Lightroom books -- Martin Evening, Victoria Bampton and Scott Kelby.
At the same time, I go along with the above posters that you install Digital Photo Professional. Whether you end up adopting Lightroom or not, DPP is good to have on hand either for quick conversions or for a reference alongside of Lightroom -- it will give you a "jpeg-like" Raw preview as a "starting point" whereas Lightroom has a different approach that may initially be a bit of a challenge.