In order to make sense, the rhythms *MUST* be viewed/printed using a 
mono spaced font such as Courier; otherwise they won't "line up".
Here's the basic legend of symbols:

LEGEND:
| first beat in the bar
* other whole beats
. half beats
: repeat
>> at end of bar = continue phrase next line
B,b bass
O,o tone
M,m muffle tone
S,s slap
Sf, Of  slap/tone flam
h heel
f finger
. touch or spacer (rest)
_ appears above notes that should be played with your strong hand.


EXAMPLE 1: This rhythm (in 12, or "compound time") shows some basic
features. The "bar" is the first line and gives the timescale and
beat subdivisions: 4 major beats (the first | and the *'s) each
divided into 3 minor beats (.). The "High" voice consists of (S)laps,
(O)pen-tones and one "slap-flam" (Sf). The underscores on the line
above say which notes to hit with your strong hand.
The "High-mid" voice spans two measures before it repeats, as indicated
by the ">>" continuation symbol. It also introduces a "heel" (h) or
muffled bass sound. (h  f) usually indicates Latin heel/finger technique.


12/8      |:  .   .   *   .   .   *   .   .   *   .   .  :|
          _           _           _           _   _
High      S   .   O   S   .   .   S   S   .   Sf  O   O
          _               _       _               _
High-mid  O   O   .   h   S   S   O   O   .   h   S   S  >>
          O   O   .   Sf  O   O   O   O   .   h   S   S
 
EXAMPLE 2: Here's a "swung" rhythm. It's basically in 4 (simple time),
and can be played "straight", but the rhythmic feel calls for the dashed
notes to be extended slightly in length, and the un-dashed notes shortened
to compensate, giving more "bounce" to the rhythm. Also note the HIGH voice
has a lead-in note; that is, the rhythm "starts" there even though its
downbeat is at the beginning of the bar.

4/4     |:  .   *   .   *   .   *   .   |   .   *   .   *   .   *   .  :|
        _       _       _       _       _       _       _       _
LOW     O-  O   S-  S   B-  S   S-  S   O-  O   S-  S   B-  S   S-  S

        _               _               _               _ (lead-in) S
HIGH    S-  .   .   S   S-  .   O-  O   S-  .   .   S   S-  .   O-  O

EXAMPLE 3: Here's a Latin multi-conga rhythm (one person playing 3 drums
arranged in front of him/her). Notice there's only one line of underscores
which applies to all 3 voices; this should be enough to determine how the
hands move. The small "s" slaps are "less emphasised" notes, or closed slaps
on the conga. Note that some other notation systems may use upper/lowercase
to indicate which hand to use.

4/4         |:  .   *   .   *   .   *   .   |   .   *   .   *   .   *   .  :|
            _       _           _           _       _           _
Quinto      .   O   O   O   .   .   .   .   .   O   O   O   .   .   .   .
Conga                       O       O                       O       O
Tumba       B           s       O   O       B           s       O   O

Hope all this helps!