First and foremost, LORE is the most important skill in the game.

Lore lets you create OP spells and Lore lets you pass the most important persuasion checks. Lore by being a Magic-centric stat, also makes Mage builds the strongest in the game by default.

There are two ways to play this game, either go full Mage and Nuke the field, or be a Melee build and rely on fast auto-attacks/crits with the occasional martial skill to CC opponents + important magic buffs. Yes, its mage or melee, no there isn't a good range build in the game, you can try but you won't have fun.

As a Mage you want your starting Attributes to be:
Might 8
Finesse 10
Quickness 10
Resolve 10
Vitality 8
Wits = As close to 19 as you can get

As a Melee you want your starting attributes to be:
Might = as close to 19 as you can get
Finesse 10
Quickness 10
Resolve 10
Vitality 8
Wits 8

Mage Attribute priority: WIts to 19, then Finesse to 19, then Quickness to 19 in that order.
Melee Attribute priority: Might to 19, then Finesse to 19, then Quickness to 19 in that order.

Note that you also use the same attribute distribution on your companions depending if theyre melee/physical or mages (Note, a certain songstress is a mage).

The reason you want to level those skills up first is because the first attribute is your DAMAGE attribute, Finesse when combined with how broken Leather armor can be gets maxed out second, and Quickness is levelled up as last to make you attack faster in general up to a minimum of 1sec between attacks.

As for your background, you really want War Mage for that extra Lore in the beginning and thats where all your points should go into as a mage starting out. That and Parry combined with Arrow shield(Agility Talent Tree).

If you're playing Melee, pick the background that gives you the most stats in your primary weapon. Theres a guide someone made here that outlines what background gives what so I suggest checking them out.

As for Starting Class, if youre a Mage spec into a weapon that has a shield and/or javelin early.
Melee can pick whatever starting class they want.

DONT WORRY ABOUT SCREWING UP YOU CAN CHANGE EVERYBODYS BUILD LATER.

If you're playing Melee, get ARROW SHIELD in the agility talent tree if you're not an unarmed build. It makes it so you can use your Parry skill for dodging too. That means you only need to level parry if you have arrow shield on.
Focus on Talent trees that benefit your weapon's damage and focus on improving your basic attack damage. For example the Unarmed Mastery Perk from the Power tree for Unarmed characters or the Duelist perk in the Agility Talent tree for one-handers. These abilities will maximize your auto-attack damage, which is what you want. As Melee your rotation should be, Skill -> autoattack -> skill -> autoattack.

Now, as for mages...
Leadership Talent tree: Abundant Arms I -> Bandolier -> Arbiter of Knowledge
Magic Talent tree: Magical Prodigy -> Expanded Mind I -> Expanded Mind II

Those are the main talents you want as a Mage, the rest is up to you. You could also pick up Arrow Shield like melee builds do but depending on how you play you might never need it.
Protip: Staffs are a trap weapon, dont invest in them.

Regardless of if you play melee or mage here are some important spells or talents to have.

Both: Spectral Blur/Restoring Touch(or 1 quick action healing spell), Arrow shield(Agility Talent Tree)
Mage: Arcane Charge(Magic Talent Tree)
Melee: aura of decay, polish arms, haste, Sunder(Power Talent Tree)

Heavy Armor is useless in the game. It slows down your attacks, only works when you're hit and enemy AI actively avoid you.

Oddly enough AI will go out of its way to attack Cloth Armor characters because it knows theyre the squishiest and easiest to kill. So where does that leave us?

Leather Armor is the best armor in the game. It absorbs more damage than cloth and unlike Heavy armor it doesn't slow you down AND it has the added benefit of avoiding being hit all together.

That is why earlier in the guide after I told you to max out your "damage stat" I told you to level up finesse. Its that stat that makes it more likely for Leather armor to completely deflect damage. That means NO damage.

But thats for armor what about weapons? Well if you're a mage its in your best interest to ditch your staff and find a shield and javelin. I'll save you the details but Staff doesn't scale well in dealing damage.

As for Melee characters, the sky's the limit for what weapon you want. Two-hander? dual-wield? Shield and sword/javelin/dagger? You name it! You can even go fully unarmed and that works just as well! If anything Unarmed is probably the best melee build in the game just because it uses 1 skill to avoid every damagetype in the game. But I digress.

In Summary

Mage: Wear Full leather armour set with Shield and Javelin
Melee: Wear Full leather armour set with your choice of weapon that isnt the staff.

I hope this guide has helped you in dealing with the option overload when it comes to how to properly choose a Build. I needed to go through almost 3/4ths of my first playthrough and several online guides after 50hrs before I finally understood these concepts.

Hopefully now you wont have to go through the same thing.