Help with bukkit server

I made a bukkit server and I am able to join it, but my friends are not able to.. I have try to portforwarding for my minecraft server, but it did nott make a difference for my them... Can anyone help me with my server problem? What do you think my problem is..? I have tried asking people on other forum sites, but I ended up getting no response or ones that did not help my problem at all.. I am not a very good at internet stuff, as in these problems with the connection... So please do not expect much from me D;