<human>: Condense the text into a few key points

As the title says, my fiancé and I currently live in a house owned by my mom. We want to buy it from her, in order to fix it up and either rent it or sell it.  

Our financial situation has been very strained the last couple years, but I have been offered a promotion and will be getting a significant pay raise, but we both have low credit scores.  

What can we do to pull our credit scores up to qualify for a home loan? It would be nice to be preparing to purchase it by March 2015. My fiancé was recently approved for a credit card card to buy an iMac (for school), so I was wondering if it would be good for him to apply for another credit card in order to have a better debt-to-credit ratio. 

Sorry if this has been answered elsewhere, I did look in the FAQs before posting.
<bot>: My fiancé and I, both with sub-600 credit scored would like to buy a house from my mom for about $60k. How can we raise our credit scores by March 2015 to make the purchase?