Is adobe photoshop lightroom the best imaging software for photographers?

It really depends. Most of your commercial photo editing software packages contain the same tools. I know that PS has several additional options that some do not. I am best versed in Macromedia Fireworks, but many people would prefer PS over it.

It is probably the most supported. There are tons of tutorials and help forums out there to help with it as apposed to some others, and it is offered as a class at most community colleges. It is probably the best for learning. I would suggest you get the trial versions of several programs and use what ever you are most comfortable with.