First you have to make sure that your connected to gnutella in the row of LED lights in the top right when the first one is green then you are connected and it should stay connected.

As for helping to get downloads to work.

If your having trouble finding something then try to make the search a little more general like use just the artist name.

When downloading try to download off the ones that have a longer rank bar and + signs next to them that means you can download off more than one source so there is a better chance it will work.

If your current downloads run out of sources, unavaible, no push route or doesnt start after a while you can right click it and select Find more sources which will search for more sources so it can hopefully start.