Set bonuses are still a mystery to me other than I know they exist. The only set gear I ever get is Cutting Beam (Omega rep(?) kinetic/high damage turret) due to it pumps out nice dps no matter what other energy weapons I'm using and then I don't get anything else in the set.
So you have the Kinetic Cutting Beam. So do I. Look at its info to look at its set bonuses. The first one, for having two pieces of the set, is a 2.5% chance to get a) +10 weapon power, b) +500 current weapon power resistance, and c) +500 maximum weapon power resistance. Parsing that, what that means is that for every shot you fire (not just from the cutting beam) you have a 2.5% chance (1 in 40) of getting a buff that increases weapon power, resists decreases in weapon power, and resists anyone trying to debuff your max weapon power. In City of Heroes terms, think of this buff as if you got +10 endurance, made you impervious to endurance drain, and made all your attacks cost basically nothing (ala conserve power). Except in STO, that comes with increased damage because your beam damage increases with weapon power. You're usually firing about once per second or once every 1.5 seconds in heavy combat, so this buff happens about once a minute for 3 seconds. Not bad.
The second one says for every hit you take there's a 1% chance to reduce all incoming damage by 99% for 2 seconds with a minimum cooldown of 30 seconds. In other words, for every hit you take there's a 1% chance to basically become invulnerable to damage for 2 seconds. If you are fighting normally you might get hit once per second or so, but if you're tanking or in combat many vs one you might get hit as much as two or three times per second. This buff might trigger once every two minutes, or as much as once every thirty seconds. Its not fantastic, but its not bad either.
So how do you get these? Well, the other two items in the three item set are the Universal Assimilated Module and the Omega Plasma Torpedo launcher. The Omega launcher is an interesting torpedo. Torpedos normally recharge slowly. It can take eight to ten seconds to reload a torpedo launcher. The Omega torpedo can actually "store" up to five torpedos. So when you aren't using it, every six seconds the Omega torp adds one torpedo to the launcher, up to five. When you want to fire torpedos, you can rapid fire all five at two second intervals. You still have to wait for the torps to recharge, but its one of the few torpedo launchers that can burst fire a lot of torps. It is not the best torpedo launcher out there, but it is a relatively cheap torp to get (it is a rep torp in the Omega rep, 30,000 credits, 15,000 dilithium, 500 omega credits) that works well especially for newer players that maybe aren't used to balancing fast beams and slow torp firing rates combined with things like High Yield torpedo buffs. Its a nice bang-the-keyboard torp.
The console is a universal console meaning it can go in any console slot. When slotted it offers the following buffs:
+0.92% crit chance
+9.2% crit damage
+5 weapon power
+5.1 Hull regen
+22.9 control expertise
Even if you don't know precisely what +5.1 hull regen is (honestly, even I don't have the formula off the top of my head) its basically a regen buff for starships. And even if you don't care about control, the rest of the buffs sound pretty good and they are: I still run this console actually. So if you keep the Kinetic Cutting Beam and take this console, you get all those console buffs and get the 2-piece bonus basically for free.
That's how you start. Find something you like - Kinetic Cutting Beam. Look at its set bonuses. See if any sound interesting. Look at the rest of the set pieces. See if any of them look like something you'd want to have either way. If you find something else you like, and the set bonus you get for adding it also sounds good, try that. Over time how I got familiar with set bonuses was that every time I encountered something new that was a set piece, either through unlocking reputation gear or by basically getting set gear for free by running the featured mission of the week, I would look at what a) the gear did and b) what the set bonuses were. If any sounded interesting, I spent more time thinking about them. If they seemed good enough to replace what I had, I tried it out. Nice thing is if you're wrong, you can always go back and reslot. And if you're learning with the set pieces from the featured mission of the week, you aren't even spending any dilithium or reputation credits on things you later don't want. Your initial learning curve is basically free just for playing and reading.
The important thing to note about set bonuses is that none of them are game changing, but they start to add up. You have lots of opportunities to have them, and you can easily have three or four. At this moment my main is running the Experimental Romulan Beam and the Zero Point conduit module, which means I get the Plasma Conductive set bonus, which is +8.9% plasma energy damage (remember: I run Romulan Plasma weapons) and +17.8 Electro-Plasma Flow (basically energy flow) which improves how fast I can recharge my weapon power - in effect, more damage. I'm running all three Resonant Preserver items: the Resonant Transphasic Torpedo, the Resonant Disruptor Beam, and the Harmonic Resonant Tactical module. The two set bonuses I get for that are +3.6 weapon power for two-piece (i.e. more damage) and for three-piece I get a special power with 2 minute recharge and 15 second duration that, while it is up, speeds up all my weapons firing rate by 4% per second up to +40%. If you have enough weapon power to drive this and you use something like Beam Fire at Will when you trigger it, you can get a really good amount of burst damage going in all directions (I like this when taking on Borg clusters in Borg events). And I have all four of the Kobali set (warp, impulse, deflector, shields). That gives me a hull regen that gets stronger as hull gets lower, an emergency temp hull heal that auto triggers when I'm hit at less than 25% hull, and a 2 minute recharge power that auto-heals nearby allies as I take damage.
That's seven set bonuses in one ship. Each one small, but collectively it can have a lot of overall impact. And they weren't hard to get for the most part. A lot of people recommend the zero point module and the assimilated module, and it is not hard after taking those to take one weapon each to get their two-piece bonuses. The entire Kobali set was not hard to get because all of the items except one come from just running one mission (Dust to Dust) and getting the reward (the last one came with the Kobali cruiser itself) Except for the one item that is now impossible to get because you could only get it with the cruiser (the warp core) the other three are things that would be decent to have without the set bonuses, including the Kobali shield which has one of if not the highest shield hit points in the game. If you don't know what shield, impulse, and deflector you should be running, my recommendation is run Dust to Dust three times, take those three things as rewards, and use them until you find something better.