Anything you share will only appear in the transfer window once someone actually uploads it from you. You are just making your share visible to others
To start with check your ports are open: Options > login > Check ports. A web page will appear saying ports are open or closed. If closed you will need to correct this.
After adding a share, rescan your files (or restart Soulseek). Add your username to userlist then browse your shared files. If all is well you will see what other users can see.
If you search leijsten users manual you will find an excellent help guide. A great place to start.
I hope this helps a bit.