Streaming For Beginners

Hello All, I am interested in listening to streaming audio like Spotify on my home system. what components do I need to start?
Bluesound Node 2i would be a good startup streamer. Down the road you can add an outboard DAC to further improve the sound of Node 2i (for example Ayre Codex DAC). 
You can start with any home computer, laptop, tablet or smartphone you already own and run a wired connection to digital or analog inputs to start or even easier put a Bluetooth adapter on an amp line input and start with that.

I auditioned gear at a dealer recently using Plex app on on my iPhone with Bluetooth connection to the amp streaming from my music library at home and it sounded very good.  Any music streaming software or service you choose like say Spotify for decent sound and wide selection will do. 
+1 for Bluesound Node 2i as a great place to start with the idea of stepping up to a better outboard DAC down the road if you really get into it.  But to really take advantage of it, I suggest subscribing to a good lossless streaming service like Qobuz or Tidal which stream at CD or better quality.  Node 2i retails for $550 but can be had for less.  New, used, or refurbished Node 2 or Node N100, earlier models in the Bluesound lineup which all utilize the same user friendly Blu OS user interface software would also be good places to get a start.
Lots of possibilities, depending on your system. A list of what you now have would get you relevant advice.
Lexicon DC-2 Digital Controller 
Sherwood A/V Tuner Preamp 
3 channel amp
2 channel amp
DVD player
DVD recorder 
Reel to reel player 
Cassette player
5.1 sound

The simplest, least expensive way to begin is with a Bluetooth receiver plugged into one of the analog inputs on your amp. That will let you test the concept using Spotify, Pandora, Amazon Music, internet radio and other sources. The quality of Bluetooth transmission isn’t what you get from a CD but it may be good enough for awhile, particularly if you pick a receiver with aptX HD built in. One of my friends with a full McIntosh stack and Nola speakers is quite happy with a $149 Bluetooth receiver for casual listening.

Pick one with good customer reviews from this page in your price range and give it a try.

If you pick one with digital output you could add a DAC between it and the amp to improve the sound but I wouldn't spend a lot of money on that solution rather than moving to a streamer that would use WiFi rather than Bluetooth.
I have a good dac, and don’t really want to pay for the dac in devices like the Bluesound Node 2, or a $5K+ Lumin;  Is it correct that all I would need to get Tidal and Qobuz is something like a $70 “KEiiD WiFi & Bluetooth (CSR 5.0) Wireless Stereo Receiver for 2.0/2.1 Home Audio System Optical S/PDIF“?  Anything better at a reasonable price?
For a Few Dollars More.  You could get a Schiit Modi for $99.  Then you could go USB out of a tablet or laptop to the Modi then analog into the Sherwood.  That opens up the option of doing a Trial subscription to Tidal or Qobuz and testing higher resolution content up to 24/192. If you have eclectic music tastes you can stream Radio Paradise FLAC 16/48 for free through a browser tab. 
No knowledge of the KeiiD WiFi receiver but considering its price and reviews if you want to stream from a phone or tablet it's worth a try, especially since you can easily return it to Amazon if it doesn't work.
I really wish we could have stickies here this question gets asked constantly these days. Admin would it be possible to put a Streaming FAQs sticky or something like it together?
I am only using the Sherwood preamp for a phono loop to my turntable and for the occasional tuner listening. The Lexicon DC-2 is my primary preamp. Can I connect the streaming thru the DC-2?
From looking at pictures of the rear of the Lexicon DC-2, you have available both audio RCA style analog inputs as well as digital spidif style digital inputs.  The spidif inputs make use of the DC-2's DAC, the audio RCA inputs need to make use of a DAC external to the DC-2, such as the internal DAC of a network player such as a Bluesound Node, or of a separate outboard DAC.  A Bluesound Node could be hooked up by either connection, but given that the DC-2 design is over 20 years old, it will more than likely be bested by more contemporary DACs, such as the internal DAC of a Bluesound Node.
"I have a good DAC and want to pair it up with a $70 steamer I saw on Amazon." Give it a try, you're only out a small amount of money if you're not happy, but I would suggest that what you're feeding the DAC matters. Keep in mind also that the app(s) you use to access streaming services and your stored music vary a lot. One of the best things about Bluesound is their app. 
Thanks to everyone for their input on this helpful advice. I will have to go to my local audio dealer and give the Bluesound Node a listen. 
If you want to keep it really cheap and simple and let your existing equipment do all the lifting, get an Amazon Echo Dot. Until a month ago I had a similar setup with a DC-2 into a Sherbourn 7/2100a. I used the Echo for all the streaming stuff, Pandora, Spotify, Tunein, and to stream music from my computer. It uses the audio cable with RCAs on one end and earphone jack on the Echo end. No fuss no muss. I also have small stereos in the kitchen and bedroom with Dots, and they can stream a station simultaneously like a Sonos system.
Sounds like an idea for starters like myself just getting into the streaming spectrum. 
When I first  started out streaming but not wanting to spend a lot at first..  I went with the AudioEngine B-1 bluetooth with a chromebook for source.  RCA out with a decent interconnect to your amp and your good to go.  Latter on you could step up by putting a dac between the B-1 and your amp.   DH Labs toslink cable is  a great  choice for this.