There's a lot that goes into getting your first lightsaber. I've personally spent the past month looking into it, and here's what I've found:
"Eh, I don't really want to put a lot of time and money into getting a lightsaber. I just want something to swing around."
Alright, there are a couple options for you if that's the case. There's the classic fold-up lightsaber, which has always been a favorite of mine, but you could also go for something a little more fancy.
"I want a high-quality, solid lightsaber, but I don't want to have to do any work."
This is a pretty common category, and you have a lot of options here. The only really high quality mass-produced lightsabers I've found are the Hasbro Black Series lightsabers. If those aren't your style, you can go to the custom lightsaber makers like Ultrasabers, or Saberforge. I'd be a little wary of these sites, however, as they get a fair amount of negative feedback. Ultrasabers has been said to have low build quality (e.g. gluing instead of soldering connections), and Saberforge lightsabers take a massive amount of time to fabricate and ship. Personally, I'm a big fan of saberforge, but their sabers can get awfully pricey and take a long time. EDIT: Supposedly, there have also been reports of the owner of saberforge not taking criticism well and getting mad at customers, so take that as you will.
"Money be damned. I want a work of art."
Well, lucky you. I'd look in the direction of Vader's Vault and Genesis Custom Sabers, as they both do commissions and make really high quality stuff.
"A lightsaber's not worth anything if you don't build it yourself, right?"
Good point! Making your own lightsaber can be a really exciting and fulfilling experience. You're going to want to start with the Custom Saber Shop. This place is really fantastic for so many reasons. They have a wide variety of different hilt pieces, so that you can design your lightsaber to fit your exact needs. They even have a lightsaber building tool that allows you to see what your lightsaber will look like before you buy the parts. There's also a varying selection of soundcards and LEDs, so that the sabers can fit both to your vision and your budget. Unfortunately building your own lightsaber is gonna require learning some basic knowledge of electronics, but it shouldn't be very difficult to learn.
Hope this helped!
EDIT: Just some more information on the electronics that have to go into making a lightsaber. The electronics a hilt needs are the following: An LED, a battery pack of some kind, a switch, speakers, and a soundboard. The soundboard is going to be the most expensive component. For a starting saber I'd reccommend the Nano Biscotte Sound Module V2. You can find all these parts at the Custom Saber Shop. They're out of stock with a lot of these things a lot of the time though, so you'll have to be patient. I alsohighly reccommend visiting their forums and watching their tutorials before buying anything so you know what you're doing. Don't just blindly buy the stuff I put in the links -- they're really just to give a sense of what you're looking for.