It's been a while since I've done a proper dungeon guide video, so here you go. Lost City of the Tol'vir is a level 84-85 dungeon for 5 players. It is located in Uldum near the bottom centre of the zone. There are 3 bosses (General Husam, High Prophet Barim, and Siamat) and an optional fourth (Lockmaw). On Heroic difficulty there is another boss (Augh) that joins the encounter with the optional boss Lockmaw. This instance is easily soloed by a level 90 character (I haven't tried Heroic difficulty yet).
I used to be pretty good at dual boxing a Protection Warrior and a Retribution Paladin. The last time I really did it though was over a year ago and with the new expansion a lot has been changed. I haven't really played a Protection Warrior in over a year either. Oh well, that just means I need more practice.
I decided to jump back in to soloing dungeons by not really soloing dungeons. Yes, there are two characters, but I'm playing both of them. For those interested I use ISBoxer to help control the second account, in this case the paladin. ISBoxer lets you map certain keys to only be passed to the second account. For example, I have all the NumPad keys bound to the main action bar on the paladin. This allows me to have the warrior's Warcraft client as the foreground application and press a NumPad key and it is passed to the paladin's client in the background. I'm using a Razer Naga MMOG Laser Gaming Mouse and a Belkin Nostromo Speed Pad n52 to help control the paladin, as well as an attack macro.
There are some people out there that believe (falsely) that because I'm playing more than one character at a time I must be botting (having the computer control the second account). This is not true. For everything the paladin does I have to press a button to make it happen. I use macros (which are part of Warcraft) to make this easier but I still have to control everything he does. I have the warrior set as the paladin's focus and a macro set up to Follow Focus. (/follow focus). I have another, as I said before, to attack the focus' target.
The Stonecore is located in Deepholme at the Temple of Earth. It is a level 82-84 dungeon with four bosses: Corborus, Slabhide, Ozruk, and High Priestess Azil. There are also a few tricky trash groups to watch out for.
Throne of the Tides is a level 80-81 five-man dungeon located in Vashj'ir. To get to the entrance you must swim into the giant whirlpool in Abyssal Breach. There are four bosses: Lady Naz'jar, Commander Ulthok, Erunak Stonespeaker, and Ozumat.