Pulled this off of MSN's front page
Projects for Experts
The following projects are probably best saved for professionals:
Major kitchen and bathroom upgrades
These projects not only require demolition but reconstruction in most cases. They also require electrical and plumbing expertise. Not recommended for the beginning do-it-yourselfer.
Major landscape and exterior improvements
Larger exterior projects (such as installing a brick patio, replacing a driveway, or painting the entire house) often require special skills or experience. Materials and tools involved, such as hot blacktop or a concrete mixer, can be hazardous.
Replacement or upgrade of plumbing, electrical, heating and cooling systems, roof, windows, or doors
When it comes to your home's operating systems, it is almost always necessary to hire an expert. Windows and doors are less technical and can be handled by an experienced do-it-yourselfer.