I am a casual LOTRO player that is pretty new to the game. I am trying to help out with the low level content, and will try to respond to any comments/questions as soon as possible.
I chose burglar because I think a good general leveling guide should be as middle-of-the-road as possible. Every class has some amazing strengths, and you don’t want to emphasize any of them in a position like this, I think (except as asides). Burgs can do some nifty things but most of their real power doesn’t come until they pick up some traits (leafwalker and other gambler traits in particular). They’re medium armor – neither total squishies nor powerful face-tankers. They don’t have pets, which really changes how you approach some things. They don’t have ranged weapons except for maybe Stoop for a Stone (hobbits) or throwing axes or hatchets (which many burgs don’t bother to use, probably due to their expense) – and a slight majority of classes are melee for the most part so this is appropriate. Class item development isn’t essential for a burglar, although it’s nice. You have to think about staying alive in melee combat but you aren’t constantly dancing with death either.
And it is fertile ground for discussion of how you develop your own strategies and advanced tactics, because burglars leveling past 20 really need to think about that – you can get away with button-mashing up to a point, but if you’ve already gotten good at handling two normal mobs at a time, you’ve got a huge advantage going into Lone Lands/North Downs and beyond. Every class needs to sort of reset into advanced tactics at some point if it’s your first time playing them, and it would be good to have that in mind as the leveling guide goes on. Burglar is a good choice for that in my opinion.
MiddleEarthInitiative 
I want to mention why I chose burglar.
I chose burglar because I think a good general leveling guide should be as middle-of-the-road as possible. Every class has some amazing strengths, and you don’t want to emphasize any of them in a position like this, I think (except as asides). Burgs can do some nifty things but most of their real power doesn’t come until they pick up some traits (leafwalker and other gambler traits in particular). They’re medium armor – neither total squishies nor powerful face-tankers. They don’t have pets, which really changes how you approach some things. They don’t have ranged weapons except for maybe Stoop for a Stone (hobbits) or throwing axes or hatchets (which many burgs don’t bother to use, probably due to their expense) – and a slight majority of classes are melee for the most part so this is appropriate. Class item development isn’t essential for a burglar, although it’s nice. You have to think about staying alive in melee combat but you aren’t constantly dancing with death either.
And it is fertile ground for discussion of how you develop your own strategies and advanced tactics, because burglars leveling past 20 really need to think about that – you can get away with button-mashing up to a point, but if you’ve already gotten good at handling two normal mobs at a time, you’ve got a huge advantage going into Lone Lands/North Downs and beyond. Every class needs to sort of reset into advanced tactics at some point if it’s your first time playing them, and it would be good to have that in mind as the leveling guide goes on. Burglar is a good choice for that in my opinion.