At level 80, I skipped Cataclysm and went straight to Pandaria. Even as my warrior leveled up, and that heirloom axe increased in iLvl along with me, Dugi still ranked that iLvl 87 sword higher. I kept picking up new 2h weapons, and Dugi kept rejecting them in favor of that Wrath sword. That's when I noticed that all of these Pandaria weapon drops, even weapons 20 iLvls higher than the Wrath sword, had secondaries under 20. So even though Dugi Gear Advisor is showing that a new weapon would provide a DPS increase, it still prompts me to re-equip that Wrath sword every time I equip a new weapon. Meanwhile, I've kept the heirloom axe in my bags, assuming that at some point its stats would once again beat whatever I had equipped, but nope, it doesn't, according to Dugi.
Research instances appropriate for your level online. Running instanced content is the single most important thing you can do, at least up through level 85. Instead of focusing on questing, focus on dungeons. A quick search for “WoW dungeons by level” or similar will help you find the right instances for your level. Keep in mind too that many instances are faction specific, so make sure to check Horde or Alliance specific lists!
Never ever pay for leveling guides. Want/need to learn about and use. Dugi is hosting a contest where you can get. Saharun is one of croatia's loveliest but least known spots (picture: alamy). Open my map to see where the nearest quest takes place and go there, through the questtracking you can quickly see what is to be expected of you or even when you look at your tooltip while hovering over mobs. It sounds unrealistic but the video promotion of the guide clearly shows how you can do it. Unfortunately it is a website and you may have to tab out if you aren't sporting a multi-monitor set up.