HTPC For Dummies question.

Since I always hear Mini used as HTPC, I thought I'd display my ignorance of the topic.
(It may be easier to just point me to an HTPC for beginners thread but there may be a quick answer )

Our viewing is strictly from DVR, real time and Netflix streaming in that order. Not really any other modes. I have never used TV to dislpay computer pictures. I sometimes use computer to play Pandora, but no music library of my own I'd care to tap into.

I recently acquired my 2012 Mini (specs in signature). By definition does an HTPC need to be dedicated to the HT, of can your everyday computer also easily be used for HTPC benefits as well?

Mini is connected to my Wi-Fi router (across the room) via ethernet.
Living room BD player connected to Wi-Fi router via ethernet (current Netflix stream method)
Bedroom Apple TV (2?) connected to Wi-Fi router via ethernet (current Netflix stream method)
Living room has Xfinity HD DVR XG1-A,
Bedroom has Xfinity RNG-150N box
Modem: TM822G Motorola
AVR Denon 2313 Ci

Remember, you were warned of my 'Dummy' status up front.
PS. the Mini's drives are not fused. I have a 3 TB USB 3.0 external drive w/ 6 partitions connected to the Mini.

 

I have no clue what those things you mentioned are so I guess I'll start looking into them to see what they are and how they are used. So I could use my mini as my normal computer AND use it at the same time to fulfill all my TV watching needs w/o the HD cable boxes? Is it relatively straight forward or quite intricate to get all these services/ apps? What kind of monthly costs do you incur compared to your old cable bill days? Is it a lo more work to find and watch shows and movies? I'm guessing my ultra un-tech wife might have challenges finding and playing her shows??

--- Post Merged, Jan 12, 2016 ---

So, start with displaying my desktop to learn how the connection works (any hints on this step ), then look into the ways mentioned by David58117 to run on my mini, to then send to the TV.

I vaguely recall when I hooked a laptop to my main HT TV (73" Mitsubishi DLP WD-73734) that t was not good at all at displaying the computers fonts etc. Would that be different because the content data type's would be TV friendly already?