I'm trying to set up a samba server on my network. I do all of my configurations, but when I run smbclient to see if the server is working correctly, I get this is error:

NT_STATUS_LOGON_FAILURE

I have no idea what this means. I did some googling on it, but nothing really useful showed up. Any ideas what this is and what I can do to fix it?

This means exactly what it says - you are not providing the proper password for the user (you knew that though). The problem is that by default the samba server uses 'nobody' as the default guest user. 'nobody' has a password field set to 'x' in /etc/password. nobody cannot be used as a login account.

Here is what i did to enable a guest(password less) login:

edit /etc/samba/smb.conf
remove leading ';' in front of the 'guest account' setting
and changed it to:
guest account = smbguest

create a guest account smbguest in /etc/passwd
useradd smbguest

edit /etc/passwd (as root)
remove second field 'x'. remove home directory. you should be left with something like:

smbguest::1001:100:::

My intend was to setup a shared folder using a guest account that i only i can write to but can be read by anyone in the office. here is some relevant stuff from my smb.conf:

workgroup = WORKGROUP
hosts allow = 192.168.1. 127.
guest account = smbguest

[shared]
comment = Shared
path = /usr/local/shared
browseable = yes
writable = yes
public = yes
guest ok = yes
write list = @wheel

Also, by default running smbclient resorts to using $USER environment variable as the user. If that user doesn't exist on the samba server, you won't be able to login. To change the user:
smbclient //server_name/share_folder -U bob%password

the %password is optional.