Newbie’s guide to Equipment

Armament:
Get a Calibur to start. This is the ultimate multipurpose sword, and will serve you well all the way up to 5*. I would also recommend a status alchemer (Volt, Cryo, Firo), as they are more effective against constructs, the enemies you will probably want to keep your distance from. If you want to play bomber, you can try working up a Blast Bomb or Haze Bomb line (fire or ice), but keep in mind most bombs are dramatically underpowered until they reach their 5* forms. Don’t use any weapon line that doesn’t go up to 4* at the very least. (namely, hot/static edges and assorted 0-1* swords/guns/bombs)
Armor:
Wolver gear is popular for a reason. It provides similar defenses as the Cobalt line, and better bonuses to boot. Other sets to consider as a main armor are the Spiral Demo series, the Magic Hood/Cloak series, and the Spiral Plate Mail series. The reason is that all of these sets culminate in 5* forms that give normal/elemental defense, or in the case of the Spiral Demo series, greatly enhanced weapon power (Mad Bomber). As with weaponry, don’t pick lines that end at 3* or below.
Why is elemental defense so important? Because Puppy Turrets are found in almost every single level, and due to their long range and aggro radius, they are the most difficult to dodge. This is particularly true if you are facing down other enemies at the same time. An additional reason is that in T3, Puppy Turrets deal pure elemental damage (most other monsters still deal some amount of normal mixed in). Piercing defense is least important, as sources of piercing damage are almost all very short-range or melee, and thus much easier to dodge or shield. And although shadow damage from Fiends and Devilites is as dangerous as turret fire, they are seldom encountered outside of Fiend strata or Infernal levels.
Shield:
Again, due to the above reasons, the Owlite series is highly recommended. Not only does it protect against normal and elemental, it defends well against shock and fire, the two most dangerous status effects. If you truly dislike the design, then anything providing good normal defense and health are passable alternatives; just remember that you will be at a slight disadvantage without elemental defense on your shield deeper in Clockworks. The same applies, pick shield lines that go up to 5*. The one exception is the Swiftstrike Buckler (3*), but if you’re using it successfully then you don’t need this guide.

Advancement:
As you open up a third weapon slot (very much worth the 250 energy), you will want to acquire additional weapons to exploit enemy weaknesses. For a swordsman, this probably means a piercing sword (Flourish, Snarble Barb) or an elemental sword (Avenger line, or Fire/Ice Brandish if you don’t want to wait till 4*), and eventually a shadow sword (Nightblade or Faust, depending on your style). Gun loadout remains the same; just work your way up your chosen Alchemer line. If you are preferentially a gunner, you may want to start the Magnus or Silversix/Blackhawk line for piercing damage (the former is better in most situations, as it deals pure piercing). For bombs, the freeze line of the Haze series is excellent for crowd control; the fire line is better for adding some damage. If you are a bomber, you may also want the Blast Bomb line and the Spine Cone line.
Continue building your chosen line of armor and shield; unless you are paying real money for your CE, then odds are it is too expensive to start a second line this early on. Once you do get the funds, you may wish to consider a secondary shield (Bristling Buckler line, Skelly Shield), and a normal/shadow defense set for tackling Fiend strata.

As always, any guide should be taken with a grain of salt, as play styles vary tremendously between players. What I find hard, you might consider a piece of cake, and vice versa; therefore, pick your gear accordingly. The only hard and fast rule is to have fun!

Edit: Suggested Skelly Shield series in place of Crest. Chances are, if you can obtain a Crest you don't need this guide. Thanks MLC! =P