It is very easy to make with an exacto knife. The cuts should be simple enough to attempt with scissors, but I've never tried it so I can't guarantee the results.
The templates you will find here are formatted for 8.5" x 11" (letter size), but this should work just as well on A4 paper.
You can sign up for a chance to download the PDF file for similar card with a flying stork at www.makeanything.net The stork is perfect to accompany a baby gift.
Step 1: What you will need
One sheet of red 8.5" x 11" light cardboard stock (construction paper would work)
One sheet of green 8.5" x 11" light cardboard stock (you could try construction paper, but it might be a little too flimsy for this color -- the pocket might rip too easily)
One sheet regular white paper for the money pocket
Exacto knife (or scissors if you don't have the knife)
Cutting mat (or any piece of cardboard or newspaper to protect your table)
Ball point pen
Regular old white glue