Thanks, now i know why no1 liked me using mia XD
I always use MIA on international servers; they can adhere to the warning, or get called a n00b for dying IMO
Tips from me:
Situational awareness
ALWAYS keep an eye on the minimap. HoN demands constant situation awareness. When enemy heroes go missing from the minimap, get worried. You'll start to learn the general movement patterns of players, and be able to tell if they are forming a gang in an area of the map, and which of your allies (or yourself) are under threat.
If you can't see the enemies on the minimap, do not go past the river alone, or even in a pair. It's usually best to stick with your team for forays past your side of the river.
If you can't see the enemies on the minimap, beware of going into your jungle alone - they could be hunting in there. The support hero on the team should regularly be putting up wards in key locations to reveal the map so you don't get caught.
Don't be ashamed to err on the side of caution, especially while you are still learning. If you notice you have a strong hero on your team, in the mid to late stages of the game, stick with him and support him while he gets kills.
Again, always watch the minimap - I can't stress enough the importance of this. So many average players seem to be oblivious to the machinations of the game, and pointless deaths can easily be avoided if you learn to keep an eye on the map.
On that note, don't count of your teamies to call MIA or SS. They probably won't, or it will be too late, or you wont spot the message cos you are busy fighting. Look after yourself primarily, and assist team mates where possible; not dying a lot is as much assistance to the team as getting a lot of kills.
Know your role in the team
For example, if you are a strength hero, you are generally a tank, and will be getting into a fight first to absorb damage and misdirect spells.
Intelligence heroes will support the team, buffing and healing tanks and agility heroes, debuffing or disabling enemies. Do not save your nuke spells for a last hit kill - it's a waste. Decide beforehand with the team which enemy hero is the worst threat, and all focus on killing that one first when entering a battle. Once that enemy has been affected by spells that reduce their armor/magic armor/damage/etc, nuke them with your powerful spell and deal as much damage as possible. I'm thinking of heroes such as Pyro, Witch Slayer. On the other hand, don't be afraid to nuke a powerful hero on low HP if they are getting away and there is no better target around.
Support heroes are usually responsible for placing wards; it's just how the game works. Support heroes usually have a large mana pool and can farm gold quickly, and so are well positioned to buy wards at 100 gold a pop. The return on investment is incalculable, as you'll avoid getting surprise ganged, and you will likely be able to form counter-gangs and get kills. So, when people start bitching that the support hero isn't placing wards, they have a point.
Agility heroes are often also "carry" heroes, meaning in mid to late game they will carry the team to victory. In general, agility heroes are good at focussing on one enemy at a time, dealing large amounts of damage and killing them quickly to get them out of battle. Targeting enemy intelligence heroes is particularly fruitful if done correctly, as they are nice and soft and die quickly - just watch out for their spells as they can dish as good as they take.
With an agility hero you will have to be a bit sneakier, using the hero's abilities to the fullest to get into combat without taking too much damage. It is not always the best idea to charge in behind the tank, as the enemy team will know the tank is a distraction, and the real threat is the carry hero. Rather come from a hiding place off to the side, or hang back a bit until the enemy has dropped some of their more powerful spells on the tank.
On that note, try and be a team player and don't just leave the tank to die while you run off chasing a kill. If you leave him to die, the tank won't want to initiate for you next time - it's a symbiotic relationship
Know all of the heroes well
Of course each hero has their own specialities, and the above are very top level generalisations. Be sure to know each hero's strengths and weaknesses, and give a bit of thought about how to utilise that hero in battle.
It's a good idea to go and read through the hero encyclopaedia thing in the main HoN menu. Yes there are a lot of heroes and it may take a bit of time, but if you want to improve, you need to know exactly what each enemy is capable of when you come up against them, and beyond that, be able to realise what sorts of combination effects groups of enemy heroes can unleash. This way you will know what to avoid, how to counter attack, and which protective items will help you best.
I guess the take away from the above is don't be too lazy to read all the descriptions of things. I'm still sometimes amazed that people ask dumb questions that are answered in the spell and item descriptions.
Finally, perhaps you should stick to a few of the easier core heroes and become proficient with them before branching out into the more extravagant and complicated heroes.
I hope this helps; let us know how you're progressing
PS: Don't be afraid to simply mute/ignore the assholes. People that act like HoN is THEIR GAME and you are merely a guest in their little HoN world aren't worth arguing with. Just learn the game and enjoy at your own pace. What a lot of players forget is that they all sucked at the game type (DotA, HoN, LoL) at one point; we all had to learn once, and the best way to learn is through trial and error.