First time user with some questions, My company has bought land to build a house and than sell and i was wondering under what type of account i shall place this. In addition, we have subcontractor's and material going to these, under what shall i place these
You're going to need some accounting knowledge to handle this business correctly, more than what I can answer here. You need to know what type of accounts these are, like what is an expense account and what is a cost of goods account, and what are Assets and Fixed Assets? Otherwise, it doesn't matter that you get the answer to this specific question, you'll post things wrong and they won't get a Profit and Loss Report or a Balance Sheet that's accurate. I'm sure you want to learn how to do your job properly. I think my book will explain all this to you, or pick up any accounting book and start studying!
Land is a fixed asset, balance sheet account.
Subcontractor and Materials depends on if it's a spec house, or if you are just deducting it as contractors, you could call them Cost of Goods. 
