So far I have paid him in checks or some material from home depot.Is it enough to write down all payments/material provided to the contractor and have him sign and acknowledge that all this is received?

My biggest advice, never, ever let them get ahead of you on draws and I would advise until a level of trust is established that you purchase all the materials.  

Sometimes that means doing things myself, and a lot of the times it means coordinating all of the resources that need to come together to make things happen (people, money, materials, etc). 

I did keep and file electronically copies of all receipts as well as descriptions of all work done and materials required to complete the work.

Things you must not doYou must not;i) Commit an act of bankruptcy; or fail to pay me on time any money you have to pay me under this contract; orii) Pay any repayment/s with a check, direct debit or other instrument that is subsequently dishonored by a bank; oriii) Fail to comply with any condition of this loan contract; oriv) Make any material false or misleading representation.6.

option A) - contractor too busy to take this job, find another one.option B) - contractor not excited about the profitability of the job, has many other better jobs lined up before yours, therefore see option A to deal with this issue.option C) - putting together a number can be a lot of work, in fact if you were responsible for binding yourself to a number for a large amount of labour and material, you'd be sure to put some time into it.  

Like I said in my earlier post I did a budget staging job and I think that after some furniture sales my net cost could be down to $1500.Bearing in mind I have three to sell, one the show suite sells I can transfer the material to the second unit, for free, compounding my savings.

Ok, now that you have taken your initial step, below are some quick links to get engaged. http://www.biggerpockets.com/startherehttp://www.biggerpockets.com/meetSetting up Keyword AlertsHow to Use @Mentions on BiggerPocketshttps://www.biggerpockets.com/ruleshttps://www.biggerpockets.com/inviteshttps://www.udemy.com/biggerpockets-real-estate-investing-course/ (video with 64 lectures and approx 6hrs of material)https://www.biggerpockets.com/real-estate-investing (Ultimate beginner's guide to REI)REI can be very daunting, but, before you go searching for that 1st buy, please take a few minutes to bone up on the tips in link below.https://www.biggerpockets.com/renewsblog/2014/12/19/real-estate-investing-success-smart-tips/REI books suggested by BPershttps://www.biggerpockets.com/renewsblog/2015/11/13/7-real-estate-books-beginner-investors/ (7 absolute must read books for beginner REI)http://www.biggerpockets.com/renewsblog/2013/04/14/best-real-estate-books/?

I'll tell you as a contractor that has done work for Lowes and Home Depot, expect a 40% mark up on contractor install prices and material. 

Your time here will be well spent.You didn't mention a niche of interest, so I added the most popular three below, for your review and selection of one or all.http://www.biggerpockets.com/renewsblog/2013/02/22/buying-rental-property/ (how to buy a rental property)http://www.biggerpockets.com/renewsblog/2014/01/07/flipping-houses/ (step by step guide to flips)https://www.biggerpockets.com/renewsblog/2015/01/31/ultimate-beginners-guide-real-estate-wholesaling-2/ (Ultimate beginners guide to wholesaling)Now that you have made the move, below are some links that will help with the navigation of the site. http://www.biggerpockets.com/startherehttp://www.biggerpockets.com/meetSetting up Keyword AlertsHow to Use @Mentions on BiggerPocketshttps://www.biggerpockets.com/ruleshttps://www.biggerpockets.com/inviteshttps://www.udemy.com/biggerpockets-real-estate-investing-course/ (video with 64 lectures and approx 6hrs of material)https://www.biggerpockets.com/real-estate-investing (Ultimate beginner's guide to REI)Before your 1st purchase, please ensure you visit the below link for some tips.https://www.biggerpockets.com/renewsblog/2014/12/19/real-estate-investing-success-smart-tips/REI books suggested by BPershttps://www.biggerpockets.com/renewsblog/2015/11/13/7-real-estate-books-beginner-investors/ (7 absolute must read books for beginner REIs)http://www.biggerpockets.com/renewsblog/2013/04/14/best-real-estate-books/?