Recommending Painting procedure

Other than paint, brushes are one of the largest expenses.  Treat your brushes properly.  Do not let them dry out while using them. Do not leave them in the sun.  Do not leave them in a bucket of water as the bristles will absorb water.  If you take a break, rinse your brush out first!

If you are willing to take care of your brush, pick a good one.

If you are not willing to clean it then please use a disposable brush.  These won't carry as much paint so they take more brush strokes to cover the same area but they are cheap enough that we don't need to clean them.
 

Step 1 - Prime the house

Prime the Trim (3) and the siding near the trim (1) first so it will dry first, then work towards the main body of the house (2).

Step 2 - Paint the siding 

Once the primer is dry, start at the edge of the trim (1) and work towards the main body of the house (2) as you did when priming.  Paint the edge of the trim with the house color.  Wipe off any house paint that gets on the face of the trim (3).  Once you are working on the body of the house, one person can slop the paint on with a roller and one or more others can spread it out with a brush.  This is much faster than dipping the brush in a can of paint.

Step 3 - Paint the inside edges of the trim

While the house paint is drying, paint the inside edges of all windows.

When painting the Fascia, brush the trim along the edge of the shingles but leave an unpainted 1"-2" strip along the bottom edge.  This will be rolled after the house color has dried. 
 

Step 4 - Paint the face of the trim

Once the house paint is dry, use a roller to roll the face of the trim as shown.  Note that the trim color is not on the outside edge of the trim, only on the face and inside edges.