Welcome to the forum! If you tell people here a little about what type of photos you want to take, you get a lot of lens suggestions. And also tell us your budget, how much you want to spend will give everyone a range.
I'm a freshman in using DSLR. So I want to learn some basic ideas in this area and usually I like taking scenery photos. I will consider a zoom lens with close to medium focuses. I think DA* 16-50 is better according to the reviews, but it is more expensive. How about DA 16-45? Or third party lens below 500 bucks? Thanks！