Regular upkeep is vital to the life of your carpet!
When cleaning carpet, always use a warm water solution. The warm water allows the grime and oils to be broken down more quickly and completely. For the cleaning solution you can use any of the numerous commercial products available but a simple mix of water and vinegar works just as well. The white vinegar will pull residue from the fibers making your carpet softer and cleaner.
For stains, there are numerous treatments. Club soda works great on red wine stains. Baking Soda works great on tough grease food stains and WD40 works great on oil spots. Once the stain is removed rinse the area with a vinegar and water solution.
When cleaning a carpet stain it is important to remember to blot the affected area and never rub it. Rubbing causes the particles to ground into the carpet fibers and it can also lead to the premature breakdown of those fibers.