Before you do anything else, take the scope outside on a good night, find a semi- bright star (Polaris will do). Let the scope cool down
! (about 45 minutes) use your highest power eyepiece and put the star in focus.
Now take the star out of focus (inner focus or outer focus) you should see a dark circle in the center with symmetrical rings around it (airy rings). If the dark circle is in the center and the airy rings are symmetrical, your telescope is collimated
Check both inner and outer focus, they should be close to the same. If not you should re-collimate.
Best done with fainter stars but for now stick to the brighter ones.
Because I own 3 scopes, I use a Hotech laser collimator. its quick and easy. Worth it if you travel with your scopes to dark sites
A good guide on how to collimatehttp://www.skyandtelescope.com/howto/diy/3306876.html