Position adjustable self-illuminated panel units may be used in combination with conventional shelf supports. Preferred shelf-units include a light-transmissive panel, a shelf frame holding the panel and having an illumination element for providing a light source to illuminate the panel, and a magnetic connector electrically interconnected to the illumination element and adapted to being magnetically and electrically coupled to a source of electrical power. The illumination element most preferably includes an LED strip housed within one member of the frame and positioned adjacent to an edge of the panel. A magnetic connector includes a pair of electrically conductive side panels, an electrically non-conductive spacer sandwiched between the side panels, and a pair of magnet bars fixed to the spacer. The magnet bars define an air gap therebetween such that electrical contact may be established between the magnet bars and a respective one of the side panels. Shelf lighting systems according to the present invention will most preferably include a self-illuminated panel unit as described briefly above, and a ferromagnetic power strip for supplying electrical power thereto. The magnetic connector is therefore capable of magnetic and electrical interconnection to the power strip (e.g., via the magnet bars thereof so as to in turn supply power to the panel unit (e.g., via lead wires connecting the side panels to the LED strip).