There aren't many downsides to the care and cultivation of your garden, except the toll it can take on your hands. Naturally, they'll be dirty, but extended time spent handling soil fertilizers or weeds can also sap your skin of emollients and moisture, and expose you to any number of irritants -- including poison ivy. Most skin problems can be addressed, however, with a simple regimen of soap and moisturizer.
Finding a good antibacterial soap is the first step. Try one with a vegetable base, such as Crabtree & Evelyn Gardeners soap, which contains pumice to help get your hands especially clean and glycerin to smooth and soften your skin. A small, natural-bristle brush is perfect for getting dirt out from under your fingernails; look for one whose bristles are soft but firm. Hand creams, including those with vitamin E, can invigorate your skin and help maintain its good health. Very rough skin can be rescued with Bag Balm; it was originally developed to keep cow udders from chafing, but it works nicely on chapped or irritated skin.
If you do come in contact with poison ivy or poison oak, wash any exposed areas and apply a lotion, such as Tecnu Extreme poison-ivy preventative, which removes plant oils from the skin and is effective even after a rash appears. Another way to protect your hands while pruning and planting is to wear gardening gloves. Learn which material -- whether cotton, latex, or suede -- best suits your needs.