Beginner Turntable

I can answer some of your questions.
As far as using a TT with the Denon RCD-M39s, I see there is one analogue input for an external device.

But the output level of a TT is very low and cannot plug directly into the Denon. You would need a phono preamp which boosts the volume of the TT and then plugs into the Denon amp. Now you would have a signal from the TT that is high enough for the amp to play it. Without this preamp, you would not hear the TT thru the Denon amp.

I would suggest looking at a TT that has a built-in preamp.
Then you would save some money and be able to plug right into your Denon.

Many online stores sell turntables that include preamp and cartridge.
Here is one example...

http://turntablelab.com/collections/turntables-with-built-in-preamp-alpha/products/audio-technica-at-lp60-automatic-turntable-pre-amp

New: Rega, Pro-ject or U-turn Orbit $200-500
Used: Technics, Denon, Pioneer or Yamaha $50-400

May have to skip the mini Denon system, probably has no phono preamp- get a used 70's vintage receiver with built-in phono amp. Better sound and power. $50-200

I built a nice used system for $90! - rotel receiver, technics TT and ESS speakers. Plan on spending a year stalking thrift shops for that kind of bargain. The audiophile snobs will say you need to spend $1000 on an entry level audiophile turntable - (cartridge not included) - but I'm talking true entry level/low budget/starving student.

Check out the Denon DP-29F,it comes with cartridge and a phono preamp. Needle Doctor sells it for $150.