For me, 'detailing' is taking the regular maintenance of your vehicle to the next level. After basic washing etc, you will want to look into freeing your paint of any contamination, then exploring paint correction by using a variety of polishing compounds to remove fine scratches to your clearcoat to restore and enhance the level of gloss for you paintwork.
After this comes the protection stage whereby you want to safeguard your hard work with a sealant and/or wax to help provide a protective layer on the cars body.
Other areas to consider 'detailing' would often include, interior/upholstery, wheels/tyres, engine bay, exhaust, glass/rubbers.
Some products that I'm using at the moment to very good effect is the Sonax range. If there is anything you'd like to know, give us guys at CleanYourCar a call or drop me PM
Zach.