jedi_mike8,
There are two ways in which you can paint your figures.
1.) While the parts are still on the sprue.
advantage: easy maneuvering for painting especially the tight spots.
disadvantage: Possibility of painting messed up at joints when you put the parts together. Some paint discontinuities at joint can be seen.
2.) After you have assembled it.
advantage: Smooth paint transition on joints. Avoid messing up the paint when gluing joints or other parts.
disadvantage: Difficult to paint tight spots.
I used to paint the parts while these are in the sprue but now I prefer painting after assembly.
When I paint, I usually start with the large areas like the uniform to the details. I paint the faces and hands last.
You can probably us Tamiya Dark Yellow for the uniform of the Desert Rats. If necessary you may want to adjust the tone of the color using some amounts of any of the darker or lighter earth colors like buff, flat earth, read brown or flat brown.
While it maybe considered unnecessary, I feel that spraying is better than hand painting to achieve a flat or matte finish for large paint areas. Sometimes brushstrokes can cause lumps of paint that become a bit glossy.
I use a very fine Tamiya brush or chinese brush to do the camo patterns and other details. You need to thin the paint for camo pattern properly to achieve a smooth finish.
Adding some light washes and doing some mild drybrushing can also liven up your figure.
Let me just share with you a pic of some figures I did a while back. These are of US M1 Tank Crew sporting the old US Army desert camo. This is the original pic. After posting it here the figures have already received some additional washes and dry brushing. The eyes were already darkened and redone taking away that funny look of the TC.
Hope this helps.
P.S. You can check any arts supply store in Quiapo area for things that you might need in the hobby. I cannot really remember the names of the store.