There is an interesting short guide to pine pruning here.
Several pruning strategies are described in the guide, but here is the part about candling (I found it very useful and packed of relevant info):
During the Spring, the buds that you have retained will elongate into
candles, their size being in relation to each candle's individual
strength and vigour. To ensure that growth extension is regulated and
energy is dispersed evenly throughout the whole tree; these candles
need to be pinched back. The amount that each candle is reduced
depends on its position within the structure of the tree and its
future purpose. After the candles have extended into new shoots and
branches, it is at their tips that new buds for next year will form.
Just as in bud selection, candles growing in more vigorous areas of
the tree should be reduced by far more than candles growing in weaker,
inner areas. If a new branch or sub-branch is required the candle can
be left unpruned to extend; however it should be noted that more of
the trees energy will be directed to it at the expense of other areas.
Candles left unpruned to encourage vigour in weak areas or to develop
new branches can then be cut back to a desirable length once they have
fully elongated and hardened, this will soon be followed by the
appearance of buds at the tip.
The timing of pinching out candles will affect where the new buds that
follow will form. Pinching the candles before the new needles appear
will cause new needles to form at the base of the candle. Pinching the
candles after the needles begin to appear and start to elongate will
cause the buds that follow to form at the end of the new shoot.
Don't pinch out all the candles at once. Start pinching out the weaker
areas of the tree first and finish with the strongest areas 2-3 weeks
later. Generally, as a rule of thumb, candles growing in vigorous
areas of a Pine should be reduced by at least 1/2 to 2/3, candles in
weak areas should be reduced by no more than a 1/3.
You may consider combining candle pinching with other pine pruning strategies too (also described in the guide):
- Hard Pruning / Removing Branches
- Bud Selection
- Needle Plucking
- Shoot Trimming and Forcing Back-Budding
- Needle Reduction
Also, there is an interesting article Growth of a Pine Tree from The American Biology Teacher. Following two pictures illustrate annual and multi-annual growth of a pine: (not really before-after images you are looking for, but still very useful for understanding pine growth)
April - November
Jan 2009 - Jan 2012