Hello SLOguy,

with the way ethereum is going, the more profitable it is the more miners will join, which in turn means more difficulty getting profit out of it as the overall network hashrate rises.

If you wish to get started, you best hurry while you still can before Eth goes to Proof Of State which should be within months to a few years depending on how good the Dev's at Ethereum are.

So first step is to build a very effecient mining rig.

Choose any type of processor, meaning the lower the total TDP the better it'll be. I recommend Kaby Lake Pentium CPU's or Celeron anything lower than 54Watt should be fine as you won't be using it for anything other than keeping the OS afloat.

Motherboard - You'll need 6 pcie slots meaning x1 slots or pcie x16 slots, you can mix and match them as long as you get a cheap board that has 6 slots that work. If you don't know what x1 pcie slots are, google them.

Ram - you only need 4GB max, anything more and it'll be wasteful(Unless you plan to put something else on this rig like file sharing etc... which isn't recommended)

GPU - AMD GPU's are usually recommended for mining ethereum, Profit wise RX 480's are the best of the best, or RX 470's however finding them is like finding a diamond in a cave nowadays, so go for RX 570's or RX 580's if you can find them(Currently sold out pretty much everywhere... I'm still waiting to get a 580 lol..)

PSU - You'll want to go for 80+ Gold or Plat, or Titanium depending on how much energy you wish to save, I personally go for Titanium because I love to be efficient.

Case - Just buy a mining rig case off of ebay or build one yourself, they go for $75 not built, or $120 prebuilt plus shipping.

Software - Use Claymore's ethereum miner or QT Miner, or Genoils miner(If you can get it working, it doesn't want to work for me always waiting for packages...)

Pool - I recommend https://alpereum.ch/ for the 0 Fees and 0.2 minimum payouts, or you can go for the 1% fee and 0.05 payout(you'll lose a bit of profitability this way but its up to you if you want to get money faster rather than waiting and gaining more) the second pool I'd recommend is https://ethermine.org for 1% fee, and 0.05 payout.

Software setup - Generally most pools offer tutorials on how to set them up, however If you don't know how to do it, just look it up on youtube, should be simple enough.

Ethereum Wallet - I recomend a offline wallet not attached to any computer that you take online, potentially one like https://github.com/ethereum/mist/releases You can always take it online if you want, however if you wish to be secure, make sure to only take it online for minutes and never leave it online(Make sure your pc is secure before taking it online otherwise you'll easily be losing ether if you have large amounts...) You can also use an exchanges wallet if you want, just  make sure you trust the exchange and have secure login details that you only know(Make sure your pc is secure when logging in as well... don't want to be losing money haha...)

I also recommend using https://pcpartpicker.com/ for selecting pc parts, easy to find out how much it'll all cost(Except for the case and riser cables just google them.) I'll link a build when I finish making one.

~~Edit~~

Here's the link for the full system build I'd use and make - https://pcpartpicker.com/list/tgfpYr

Do note that the CPU does come with a heatsink and fan, and the list for the other gpu's you can buy in multiples and it'll work.
The case you can make yourself if you just google Mining rig Frame or Case, it shouldn't be hard to make, or you can buy one.