Preparing for a future mortgage application

JJH2013

My partner and I have had some rough patches in our credit history but we're looking to buy a house within the next few years. He is currently in a DMP but we are looking to clear off what's left within the next year as it's not that much anymore and with the DMP it will take ages! I have a 1 or 2 defaults, the latest being 18 months ago, so I'm hoping they would have dropped off or at least be far enough in the distance by the time we're in a position to apply.

My question is how 'clean' do our histories have to be? Would, say, 2 years of a clean record be enough? How far out of his DMP does my partner have to be? Is it worth printing off our credit files and taking them to someone to give us more detailed advice? Who do we take them to? We plan to work really hard to clear our bits and pieces over the next year or two and we want to make sure we're taking the right steps to get accepted for a 'normal' mortgage.