So I have looked this up on several sites and so no clear definitive answer as to which armor they fall under. Some people say shields are separate from armor perks (such as custom fit matching set etc) some say the skill level of light armor or heavy armor affects the rating on the respective shield of that type. Does 100 in heavy armor increase the rating in heavy shields and same for light armor and light shields or are shields separate in their entirety. Also, which would you recommend and why?

He's some detailed info. http://www.uesp.net/wiki/Skyrim:Armor

Love that site!

Any way, on there it says that the perks Custom Fit, Well Fitted, and Matching Set all benefit as long as the armor is the matching set. Although, shields do not benefit from Agile Defender or Juggernaut. They also do not factor into leveling light or heavy armor skills when hit. Shields effectiveness is based on the Block skill regardless of armor type.

It looks as though choice of shield is solely dependent on appearance, it's armor rating, and weight by itself.

ok thanks yeah I check uesp a lot I just wasn't positive on it. So you're saying its perfectly fine to do all light armor and a heavy shield? so a light armor skill of 100 would not benefit a light shield more than heavy shield?

The normal Light/Heavy shields will have their AR increase as the Light/Heavy Armor skills increase, but the amount is negligible compared to actually blocking the damage.

So really, the only thing that matters is your preferred appearance/effects.

Speaking of shields, am I the only one who thinks it strange that hold guards shields are classified as heavy armor? They're mostly wood and are as light as hide shields iirc.

In my game is classified as a light shield...