Dugi’s leveling guide is the leveling addon I’ve always used to level as fast as possible. It will show you where to go and what to do in-game, speeding up the leveling process. This is optional though, as the game already does a pretty good job at showing you where to go at all times. The addon does, however, come with a couple of other nice features and perks.
A common mistake of new players is to upgrade their gear at every opportunity, paying for a new piece even if it will only add one or two new stat points over an existing item. Likewise, investing in headgear, neckwear, trinkets, and rings at the earliest available levels can also consume valuable cash. While it might seem foolish to leave an available slot empty, you will eventually find something to fill it. Blizzard will see to it via the quest rewards you'll get along the way. In the mean time, the 1 or more you save will serve you well if you invest it wisely. The bottom line is that one can easily level all the way to the maximum relying on just quest/drop greens. The gear you get from regular questing can help you perform well in dungeons, which gets you even better equipment.

Heirlooms are special pieces of armor that level up with your character, so they have stats that are always respectable for your character’s level (up to level 110). Heirlooms that fit the head, shoulder, chest, legs, and back armor slot offer an experience bonus. The total bonus is 45 percent if you have them all. It’s also possible to acquire a ring that adds another 5 percent, but you must win a fishing contest acquire it, and that can take some time.
The leveling guides on my site are essentially speed leveling guides.  My leveling guides are the same guides I use myself to speedrun to 60 on new servers to get 60 server first.  I list many occasions where I tell the player to "die on purpose" to go faster.  I tell the player to skip certain quests, because some quests are just not worth the time/XP.  I list tricks and shortcuts to go faster so you can reach level 60 much quicker.  I am still constantly going through them over and over again perfecting the guides to make them faster and easier to follow.  For the most part, the guide can be followed without the need from other player's help, as the whole guide was made from a solo run anyways.  Although I do list quests that can optionally be done if you have a group.
Additional information for residents of Quebec only: The regular annual rate for persons applying for the Triangle credit card is 22.99% for cash transactions and related fees and 19.99% for all other charges. Some applicants may receive a higher or lower regular annual rate depending on a credit evaluation. The minimum payment is the sum of (a) interest and fees shown on your statement, (b) the greater of any amount past due or any balance over your credit limit, (c) the amount of any equal payments plan instalments then due, and (d) $10. Balances under $10 are due in full. For residents of Quebec, the period between the statement date and the due date for payment is 26 days. The billing period covered by each statement can be from 28-33 days. The Triangle Mastercard does not have an annual fee. Examples of borrowing costs (rounded to the nearest cent) assuming that all charges are purchases bearing interest at the regular annual rate of 19.99%, a 30 day month, no charges made on special payment plans and no other fees, additional payments or other changes are:

Leatherworking is a crafting profession that uses various leathers obtained from skinning to craft leather and mail armor. You can make gold shuffling leather into enchanting materials through the rank 3 bracer recipes. Battlebound for Stormscale and Warhide for Stonehide Leather. The other main market for Leatherworking is crafting the item level 850 gear. I find that both Dreadleather and Gravenscale gear sells very well.
Be aware of the seasonality of items. Check what items are used in seasonal achievements, such as Delicious Chocolate Cake or Small Egg during Children's Week. When the Darkmoon Faire is in season, Darkmoon cards and decks (Furies, Elementals, Lunacy, etc.) tend to sell well, but prices also tend to get depressed. When the Faire leaves, prices return to normal, but sales volume decreases. The same is true of things like Snowman kits, Red Holiday wear, etc. Holding onto that Snowman kit for a few months, and then listing it in July, can net you a significant profit.
The most important step in being able to buy a mount and make other large purchases should be self-evident: saving. Economize as often as you can, and don't buy anything unless you absolutely have to. You can burn through hundreds of gold even before level 20 by visiting the auction house for new equipment at every opportunity. If you do so, over the long haul you will be left with very little to show for it. Before level 20, keep your eyes on the prize: getting that mount. The mount helps you move faster. Faster movement means faster killing, faster questing, faster quest turn-ins, and faster leveling. It is the most important tool to fast leveling you can get at level 20, and infinitely more important than getting your hands on that Left-Handed Vorpal Cleaver of the Zipswitch that you could have purchased at level 23. Stay focused.

If there would be a transmog server #1, all transmog vendors would transfer there and the market would get destroyed fairly quick. In general, Roleplay-Servers like Argent Dawn or The Aldor are better server for selling transmog. On high pop servers you have a lot of other players selling stuff and as a result, low prices. On low pop servers prices are acceptable, but you have no buyers. So there is not recommendation for a server really. Its up to you.