Solar Freaks

Hi all. I recently posted a topic but I think I may have posted it in the wrong section so I`ll put it in here as well. Maybe I should have had a good look around the site in the begining anyway, I`m new to solar and all of this is new to me. I`m considering having solar panels installed but I`m confused about the different inverters that are on the market. I`m trying to find out what the MPP voltage is all about. That is, what does it mean. In the spec`s of these inverters there`s also mention of the start up voltage which I think I understand but I`m wondering if this has anything to do with the MPP voltage. Also, I believe that some inverters have a transformer and some don`t. Is there any advantage either way?? If anyone can give me some advice on all of this, It would be much appreciated.

Cheers all.