For a Panel Flow tutorial with streamlines see "Internal Flow".

However, I'm guessing that you are more interested in external flow. The same principle applies - you need to create a volume to bound the particles - so position a separate volume (e.g., box) around the region where you want to visualize the streamlines. Set the particles' seed (release point for your streamlines) as the upstream face/edge, and then set the target as the volume. To improve the resolution of the streamline paths you can use the Accuracy tool on the volume or seed face.

For more on particles/streamlines see "Particles or Streamlines".