I am looking for some advice on how to spend my perks. I started playing a warrior type but wan't sure which way to go so avoided allocating perks and hence have reached level 20 with 15 unallocated perks
Now settled on a 2 handed heavy armour. Not surprisingly I am now finding some battles a bit tough and need to sort my character out. I am getting killed too easily so need to get higher armour rating and also increase my damage ability. It hasn't been a problem yet but I also have no protection against magic attacks.
I don't want to spend too much time grinding abilities but don't mind doing a bit. I don't want to waste perks on things that soon become unimportant. eg reading the forums it seems that using improved armour it is quite easy to reach the armour cap so putting too many perks into boosting heavy armour may be a waste.
I see a lot of people concentrate on smithing and enchanting and then produce high powered weapons and armour. Is it best to concentrate my perks on those skills?
Hmmm... it kind of depends how you're planning to play - power-levelling, min-maxing, or just letting your character develop naturally.
If you're looking for maximum bang for each perk point, you don't need to max the heavy armour tree at all. 2 points in juggernaut and 1 in well-fitted will be enough if you level and invest a little in enchanting and smithing. You can then hit the armour cap very easily with ebony armour (and smithing just up to the ebony smithing perk).
Basically, you enchant some fortify smithing gear (clothes, gloves, ring, necklace), but or brew a fortify smithing potion (50% will be enough, which you can find at lots of merchants), and then you can smith ebony armour to the armour cap easily - and also give your weapons a nice boost too.
For two-handed, of course, you'd want 5 ranks in barbarian, devastating blow and sweep. I'd not bother investing in anything in that tree, but ymmv.
By my in-my-head calculation, all that is 14 perks (spread across two-handed, heavy armour and smithing first off), so you should be able to spend them straight off.
I'm not sure if you also need perks points in enchanting (or how many) to hit the armour cap as I was levelling enchanting early on, but for a start this tactic should give you a good boost to survivability and damage for a two-handed build, I think.