Most of us boil up priming solution, rack the beer to a bottling bucket and add the solution, then bottle from there.
I have some tips for bottling in this thread...
It's much easier to bottle with a bucket and boiling your sugar in a bit of water...there is a risk in priming bottles individually...and few grains of sugar too mcuh and your bottles could go boom...Glash shards and wasted beer is not fun.
You also might benefit from taking a look at this chapter on bottling from How to brew.
How to Brew - By John Palmer - Priming and Bottling
If you insist on NOT going the bottling bucket route, rather that adding sugar in the bottles, consider getting priming tabs like muntons...they are pre measured sugar tablets with the correct amount of sugar for each bottle.