IP Addressing and Subnetting

I am rusty when it comes to IP addressing and Subnetting.  Give me some good resources to look at - if there something better than what you find outside of googling it,

I have my firewall / gateway for the internal network.  I do I assure that mapping of drives from the wireless to the internal network itself is seamless.  

and explain subnet mask more to me: 255.255.255.0 vs 255.255.255.248 vs 255.0.0.0
outside the question just extra knowledge for me.  I know it gives more IP choices and range and muilti casting etc... But I forget???

The real thing I need now is this:

Seeing printers, mapped drives, any resource on the internal IP range.

Ex:

Internal:  192.168.5.XXX

Normally you give the wireless router an IP from the range for its IP and then give it - its range for DHCP on the wireless.

Wireless WAN IP:  192.168.5.XXX
255.255.255.0

LAN IP: 10.1.10.XXX
255.255.255.0

2 things - is it better and what makes it seamless to use 192.168.6.XXX
255.255.255.0

same 192.168.xxx.xxx or ???

thanks