Getting the bed level in relation to the X and Y axis is very important for getting prints to stick well and is one of the first steps you should do when receiving your Solidoodle. The first layer might have the right amount of squish in one area, but if another part of the bed is too low, that part of the print is more likely to come unstuck and begin to warp. The level is adjusted with the spring loaded screws, two at the front and one at the back. If you are using the standard kapton tape on the build platform and not a sheet of glass, you will need to poke holes in the tape in order to turn the leveling screws or print some thumbscrews and use a little super glue to screw them onto the bottom of the leveling screws. I suggest using the thumbscrew route so that you do not have to damage your kapton tape. Joosh has made a thumbscrew STL available on Soliforums.
Official Solidoodle Bed Leveling video
Leveling the bed with a piece of paper
You can check the level of the Solidoodle's heated platform by using a piece of paper to check the gap under the nozzle. It's best to do this with the platform heated to account for any change due to expansion. I also prefer to use a metal feeler gauge rather than paper, but it's hard to do that on a heated platform without getting burned.
Put the paper under the nozzle near one of the front screws and raise the bed .1mm at a time using the manual controls in the software interface while sliding the paper back and forth. Stop when you feel the nozzle start to grab a little bit.
Move the nozzle to the other front screw and adjust the screw until you get the same amount of friction as you felt with the first one. Then adjust the back screw the same way. Once you have adjusted each of the three screws, go back and check each one again, since adjusting one screw can affect another. You shouldn't need to go around the bed more than twice.
Leveling the bed with a dial indicator
The best way to level the bed is with a dial indicator. This uses a spring loaded plunger to detect changes in distance. You can mount one the the front of the extruder, and zero the reading at one corner of the bed. The watch for the readout to change as you move it around the bed and adjust the screws accordingly. Here is some video of mine in action -
Neil Martin has made an excellent mount which you can find here -
If the fit is too loose for the tab on your gauge, you can use a few pieces of tape to thicken it up.