i can/have solved a rubics cube in 20-30 seconds.
there is some great help guides found outside wikipeda try this one.
problem mostly is learing how to orintate the cube in your hand to apply the first moves.
then learning not to change the postion of the cube until you figure out what each move actually does to the specific traget cubes.
each move actually only moves a few pieces at a time where some stay in there exact postion and 1-3 move around it.
heres a guide to one of the easer ways to solve a cube layer by layer.
starting with the top .
http://www.rubiks.com/lvl4/commun/cbeclb/clbsol/clbsol_3x3.htmland a more advance "block building" technique found here with step by step slide shows.
http://lar5.com/cube/fas1.htmlthe new sudoku cube is harder then a regular cube as the postion of hte central cube is not stationary (color coded)
where the last step is to correctly swap the central pice to match the rest of the puzzle.