Making "new" guides seems kinda out of place. Not only is there still alot of information from back then available, there came alot of information up for minmaxing available for both leveling and raiding, ontop of various bis gear lists that cover patch progression aswell if necessary. Wether people like or dislike pservers does not make the various information found on their forums less valuable.
In Classic, playing different classes actually feels different in more ways than just their abilities, at least if you think about it a little. Playing a priest, you really want to find a group because that's what the class was designed for, which is both good and bad - you're stuck very slowly leveling if you're solo, emphasizing the frustration of the slow pulling, but having different classes require different gameplay can be good. If you want to play a priest you're going to have to be more social by default, just whisper the guy you see killing stuff next to you and go level together, you'll immediately have a better time of it (this part is particularly exacerbated in the beta, as there are fewer players).
However, after a while the novelty of it wears off and you do start getting a little bored of all the eating and drinking (and wondering why your character isn't getting to Kul Tiran levels of fat), especially if you hop on to BfA for a bit in between. The difference is huge and once you're used to just slamming into 5 mobs and downing them quickly it can get a bit boring to just pull 1 mob at a time and then wait and wait. The really low levels aren't that different between live and Classic in terms of gameplay however, as the small amount of abilities means combat isn't exactly the most exciting thing in either. On live you get past that pretty quickly, but it takes a while longer in Classic (especially if you're playing solo).
It’s important that you levelling in certain areas around your characters level to gain the full XP reward for slaying monsters. Below is a list of all the best location for grinding XP from level 1 to 60, these locations are good for AOE spells and should have plenty of mobs. The Level you should be before you enter that specific location will be indicated to left in a Blue Color for Alliance [Lvl 35-39] and Orange Color for Horde [Lvl 35-39] the Mobs you are looking for Bolded [Mob Name].
You will need initial funds to start this way. Buy for cheap and sell for actual price or higher – that sounds pretty easy. But you should have basic knowledge of prices and always track the market. People use to sell for cheap when they need fast gold or don’t know real value of the item. So, it’s your chance to act. If you see anyone selling an item for low price in trade channel, contact them immediately. You should use all of your trade skills to negotiate about the price to make it as low as possible. It’s important ability to communicate. Besides, it’s good to get addons to trade effectively on Auction House: Aux or Auctioneer. They allow you to scan auction, compare prices, find cheapest options, post items quickly, and many other useful tools. It is possible to make your first thousand out of ten gold you have in a pocket.
Unlocking the Lightforged will require you to complete the aforementioned Argus storylines and earn the “You Are Now Prepared” achievement. In addition, you’ll have to earn Exalted status with the Army of Light. As with the Argussian Reach, this one could take a couple of weeks, as it is time-gated. However, the main story quests should help you at least reach Friendly status with the Army of Light.