It seems LW might only have the online help now
User Guide - LimeWire
The LW 5 program keeps changing ... the beta versions have had considerable changes so that's why a userguide pdf is perhaps not offered for LW 5. Likewise LW 4 had several changes over various versions, which might be the reason they never got around to updating the pdf.
It's been suggested we do our own forum version for LW over the years but again, due to the way LW updates & changes, such user guides would become obsolete very quickly. LW 5 has had considerable changes each month or two of this year.
As a general rule, these forums do tend to provide more details about LW's tools for both LW 4 & 5.