RUDIMENTS:
Rudiments are the basis of drumming. A Rudiment is a series of strokes played with the hands. The various sticking patterns are what make one Rudiment different from another. If we look at drumming as a language, then Rudiments are the words. As with any language, the better your vocabulary, the more articulate you are.

When practicing Rudiments, it's essential to use a metronome. Practice for precision, not speed.

Here's a list of some  common Rudiments. Practice each one for 1 minute, keeping each stroke the SAME VOLUME***.

Download my  Practice Chart.

R=Right hand      L=Left hand  
***(small letters "r & l" = softer strokes, aka "ghost" or "grace" notes, are played very close to the main stroke)
 1) Single Stroke Roll:  R L R L R L R L R L R L RL R L 
 2) Double Stroke Roll: R R L L R R L L R R L L R R L L 
 3) Paradiddle: R L R R L R L L 
 4) 3 Stroke Ruff: R L R    L R L    R L R    L R L
 5) 4 Stroke Ruff: R L R L    L R L R    R L R L    L R L R
 6) 5 Stroke Ruff: R L R L R    L R L R L   R L R L R   L R L R L
 7) 5 Stroke Roll: R R L L R    L L R R L   R R L L R   L L R R L
 8) Flam:  *** lR  rL  lR  rL
 9) Drag: *** llR  rrL  llR  rrL 

VARIATIONS:
 1) Double Paradiddle: R L R L R R L R L R L L (played with a triplet feel: 123 123)
 2) Triple Paradiddle: R L R L R L R R L R L R L R L L
 3) Inverted Paradiddle: R L L R L R R L
 4) Flam Tap: lR L  rL R  lR L  rL R
 5) Drag Tap: llR L  rrL R  llR L  rrL R


COMBINING RUDIMENTS:
This is where you start applying Rudiments into your playing. By practicing Rudiments and their combinations (over and over and over), your playing will be more colorful, interesting, and you'll simply be a better drummer. Try making up your own combinations.

1) Single Stroke + Double Stroke: R L R L R L R L R R L L R R L L
2) Single Stroke + Paradiddle: R L R L R L R L R L R R L R L L
3) Double Stroke + Paradiddle: R R L L R R L L R L R R L R L L
4) Flamadiddle: lR L R R  rL R L L(flam + paradiddle)
5) Dragadiddle: llR L R R  rrL R L L (drag + paradiddle)
6) Flamacue: lR L R L    rL R L R (flam + 4 stroke ruff)
7) Ratamacue: llR L R L    rrL R L R (drag + 4 stroke ruff)
Many combinations can be made. For example, put a flam or a drag in front of a 5 Stroke ruff or roll and you have 4 more combinations...Use your imagination and develop your own style.


ACCENTS:
Adding accents to your playing will make your drumming more musical and less "mechanical" sounding. Imagine a drummer playing all his or her rolls or going through a whole solo with straight 16th notes all the same volume. It wouldn't matter how fast he or she can go, it would sound boring. By adding accents, you can make the simplest phrase come to life. Here are a few exercises which will help you add accents to your playing. As in the above exercises, use a metronome and pratice each exercise for 1 minute.
(accents are in green)
          
1)Accent on 1: R l r l R l r l
2) Accent on 2: r L r l r L r l
3) Accent on 1&2: R L r l R L r l
4) Accent on 2&3: r L R l r L R l
5) Accent on 3&4: r l R L r l R L
6) Accent on 1&4: R l r L R l r L

COMBINING ACCENTS:
These phrases will help develop the ability to  use varying accent patterns. Go as slow as you need to and make sure the Accents you do with your "weak" hand are as loud as the ones you do with your "strong" hand.
1) Accent on 1&2, 2&3: R L r l r L R l
2) Accent on 1&4, 2&3: R l r L r L R l
3) Accent on 1&2&4, 2&3: R L r L r L R l 
As with Rudiments, you can make up your own patterns and evelop your own style. Once you're comfortable with single strokes, you can practice applying Accents to other Rudiments.

The next step is to get on your drum kit and play all the accented strokes on your toms, and all the un-accented strokes on your snare. For instance, all the Accents performed with your right hand will be played on Tom 2 and all the left hand Accents on Tom 1. With time, you can add the floor tom for some right hand accents. 
Taking it a step further,  you can add your bass drum. First by playing it on straight quarter notes (1,2,3,4). Then, by hitting the bass drum WITH the accents. And finally playing the accents on the bass drum, INSTEAD OF the hands, for some very interesting and intricate syncopation. The drum set is your pallette and you're the painter. Use your imagination and "Create" music instead of just learning it.