Some of the links from http://www.stjarnhimlen.se/comp/ppcomp.html#22 are dead. If you want human-readable physical and orbital data for:

* planets, go to http://ssd.jpl.nasa.gov/?planet_phys_par and http://ssd.jpl.nasa.gov/?planet_pos (it points you to a table http://ssd.jpl.nasa.gov/txt/p_elem_t1.txt where elements need to be corrected for a given date, see http://ssd.jpl.nasa.gov/txt/aprx_pos_planets.pdf)

* moons, go to http://ssd.jpl.nasa.gov/?sat_phys_par and http://ssd.jpl.nasa.gov/?sat_elem

* dwarf planets, asteroids, etc, go to http://ssd.jpl.nasa.gov/sbdb.cgi

Also, some more data here http://ssd.jpl.nasa.gov/?constants. If you want more precise orbital elements at a given epoch (they vary through the year), use http://ssd.jpl.nasa.gov/?horizons (using the Telnet interface, first choose "Ephemerides" (e) and then "Elements" (e).