You have to understand how the math works and be in space (not sector) to see the proper stats.

Weapon Damage: As stated before a [Dmg] mod on a weapon will give it a higher listed DPS than say a [CritD] mod, however that [CritD] mod typically will give more dps in the course of a fight because the dps listed on the weapon does not take crits into account. Only damage per volley / length of time of volley.

Armor: Armor rating goes into a formula that gives you your % reduction that has minor diminishing returns as you approach 100 resist or 50% reduction. It scales linearly aside from the very minor built in penalty when you start getting near 100 resist or 50% reduction. *edit* What the resist number represents in the Effective Hull Points you would have or gain. So a 17.5 resist console would add 17.5% more Effective Hull Points, or it would take 17.5% more raw damage to crack your hull. Don't worry about the resist % it is very misleading to most people. For example if you go from 50% reduction to 75% reduction you DOUBLE the amount of damage it would take to crack the hull and give the same exact increase that going from 0% to 50% reduction would. Just remember 50-100 resist is about all the more you need before the game begins to penalize it a bit.

Shields: You shield is calculated with this formula: (Shield Base + (Skill Mod * Shield Base) + (Console Mod * Shield Base)) * Ship Shield Mod. At 100 skill you get a .3 shield mod. So lets say your shield provided 1,000 with max skill and one console on a 1.0 shield mod ship. (1,000 + (300) + (180)) * 1 = 1,480 total shield per facing. Once again they have a linearly scaling.

Tac Consoles: These add a set amount of damage per volley to the weapon based only on the weapon type and the consoles quality. If the first console adds 100 damage per volley then the second one will add 100 damage and so on. With 3 you would get 300 additional damage per volley total. Again they scale in a linear fashion.

Nearly everything in this game's math uses the + with very few exceptions like tac captain skills.