Get rid of mold in house - how?

How big is it and where? That decides whether it's a DIY job. Small patches on a bathroom ceiling, round window frames or on sealant you can deal with yourself. Gloves, a mask, window open, then a mould spray or diluted bleach on hard non porous surfaces. On plasterboard and other porous stuff bleach mostly just whitens the surface, if it's got into the material that section needs cutting out and replacing. The important part is the cause, otherwise it's back in a month. Usually it's condensation (extractor fans, opening windows after showers and cooking, a dehumidifier), a leak, or damp coming through a wall. If it covers a big area, comes back fast, or there's a musty smell with no visible mould, get someone in to find where the moisture is coming from.