hello jonathan
For schematic diagrams I recommend Eagle Cad. you can find it on http://www.cadsoft.de . there is a free edition that works up to 100mm x 80mm of pcb (on the schematic side there are virtually no limitations)
When I need to make beautiful schematic diagrams I use eagle, export into EPS and open it in illustrator. do a select all, change the font to a nice one and I get a print ready schematic.
BTW Arduino is designed always on Eagle.
going back to your circuit.
What you need around a 7805 is just 2 capacitors per side. 100n to clean up higher frequency noise and an electrolitic capacitor of 100uF or more that is used for compensating voltage fluctuactions.
when your motor starts there is a power surge and the voltage generally drops. the large capacitors compensate for this by releasing the "energy" they have "stored".
massimo