I'll have to have another crack at Dota, apparently it's one of those things you need someone to explain things to you as you go along.
Perhaps we can arrange a newbie evening for this if we get enough interest and some kind person can give an introduction to the game?
I'd be happy to take you or anyone through a game of dota but to be honest with you, nothing will teach you how to play it than actually playing it.
Just load it up and play it for a day and you'll get the the in's and out's in no time. You'll also see what kind of items people buy for which heroes and you'll understand why soon after. Some items are simply more effective on certain heroes than other items.
For example if you have a high damage agility hero you're more likely to buy an item with critical hit properties or haste to make you hit quicker because it magnifies the damage this hero can do. But you'll also need to consider HP and armour as agility heroes usually have little of both.
If you've picked a slow hitting intelligence hero, you're not gonna buy a haste item cause that would be pointless. You'd go for maximum burst damage or play a support role with items that work either positively or negatively in an area effect. For example, Mekansm (an item that heals around 250 hitpoints in an area) is a very popular intelligence hero item. But then so is Guinsoo's Staff which has high intelligence stats and the ability to cast sheep on an enemy for 3 seconds.
Dota is all about utility. It's about picking the right hero and then the right items to oppose the enemy's hero and item combo's.
If one team has 5 strength melee heroes, and your team has 5 intelligence heroes then you better win the game in 30 mins or less or the strength team will eventually overpower yours.
Generally speaking Strength heroes are late game (1hour +), agility are early and mid, and intelligence are early so a wise team will have a good combination of early and late to make sure you don't get crushed in the first 20 mins and you can stick it out after an hour
