The 40/40 caster set includes:
A wand/rod with an "Aptitude not Attitude" inscription and a memory mod.
The "Apt not Att" carries a Halves Casting Time(HCT) bonus with a 20% chance.
The memory mod carries a Halve Skill Recharge(HSR) bonus with a 20% chance
The offhand has an aptitude mod and a "Forget me Not" inscription.
The "Forget me Not" inscription gives a HSR bonus with a 20% chance.
The Attitude mod gives a HCT bonus with a 20% chance.
These two together gives you a 40% chance of getting the bonus on any spell cast and a 40% chance or the recharge bonus. The attitude and the memory mods are pretty cheap 1-3K each. The inscriptions go from 5K-10K for the A not A and 20-30K for the Forget me Not. It is possible to find them for less in game. I have paid as little as 1K for a Forget Me Not and 4K for an A not A.
A lot of people prefer a Fortitude mod on the offhand or both which gives you +30 Health, or +60. I like the 40/40 combo but I have a variety of combinations, which I load into my 4 weapon slots so I can swith off. As you play the game more, you will get more sophisticated in your weapons choices. Guru has a wealth of info on this.
Inspite of the hype, GW2 will be a while before it is released. I've been playing for 3 years and I am still doing new things. There is a lot there and every area gives your characters new weapons and skills to get better. Try buying on E-bay where you can get Cantha and Nightfall cheaply. I suggest buying new, unopened, versions, although you only need the valid serial #'s because everything is downloadable.
Unlocking things from the Balth. priest is mostly for PVP. However, you can unlock skills for your heroes, also, from the priest. If you wish to use them on your main character you need a tome to unlock them for your character. At first, skills are pretty cheap from the skill trainer, but, as you accumulate them the price goes up until it caps out at 1K. At that point, since skills cost 1K and 1 skill point, and, regular tomes cost 300g-500g, it's cheaper to buy tomes and use them to unlock the skills for your character.
As far as farming, you can use any character. Check the farming posts in the forums for info on builds, etc. I've done a lot of farming. At first, when you don't know much, just pick everything up and sell it to the merchant, rune trader, or material trader. If you start to farm, make sure you learn what the going price is for an item. If you are broke and get a perfect "Forget me Not" inscription, you can gain cash quickly. Make sure you understand the mechanics of salvaging valuable mods, etc from worthless weapons.
There is so much to learn and so little time.