There are 2 schools of thought on 2 channel listening. One thought is that you should run an entire seperate setup for 2 channel because either or botth the speakers and the amps used in Home Theater (HT) don't resolve enough detail.
I'm in the 2nd camp that says BS to the above with a caveat. When I auditioned for speakers, I auditioned exclusively on 2 channel music and the speakers I chose are very very musical. They also happen to be a great speaker for HT providing good slam and dynamics.
My receiver serves as both my 2 channel and my HT rig. I don't have the funds for both. The sound is very resolving with either 2 channel or HT and I'm very happy with what I have.
The only thing a seperate 2 channel rig could give you is the ability to use it whenever you want as opposed to having to share the use with the HT side of things.
If you have a phono stage on your receiver, then you should be able to plug the output of the turntable directly to the phono inputs.
As far as turntables go, this is the one piece of audio gear that is relatively expensive, where the law of diminishing return is at a higher price point relative to that of AVR, CD or DVD players etc.
There are 2 camps on turntables; direct drive where the motor is directl coupled to the platter or belt drive where the motor turns the platter via a belt. Both have pro's and cons and to say one is better than the other is like saying apples and oranges are the same.
As an exmaple. the previous poster mentioned the Technics as the best turntable out there. Its a good table, direct drive, very small speed deviation, built like a tank buts it tone arm sucks. I have ProJect Xpression II which is a belt drive. Its not constructed nealry as rugged as the Technics. I don't need the ruggedness of the Technics as I'm carefull with my audio equipment anyway and its not been moved since I installed it into my system. The speed deviation is higher than the Techics but still remains inaudable. I cannot detect it even when I try to listen for it. The tonearm I have is a real gem, tracks very well and is far superior in that of the Technics.
My recommendation is go out and audition turntables from companies such as ProJect, Rega, Music Hall, Marantz. Stay away from the modern Sonys, Yamaha, Pioneer, Kenwood, Denon, ION, and others as they are cheaply made and built. The older 70s vintage Sony, Denon, Marantz, Dual etc are good tables but will require some sort of maintenance unless the original owner has maintained them.
I hope this has helped you some