I had covered in the first part - Secure your Home Network, precautions that can be taken to protect the desktop and identity theft that may happen. The other important part is to protect the wireless router and the network which it creates, so that no unauthorised person can access it from outside. Lot of users use a wireless router at home and are not aware of how it should be secured.
The security issues related to wireless networks are:

1. Wireless routers have a range and it normally goes beyond 30 feets. That means a person sitting in a car beneath your house can access your network and use it to send unsolicited mails.
2. Second scenario is that you have secured your wireless network but you have not used a strong key or password and someone gains access to the admin page of your router. If this happens he may be able to change all the settings that you have done.

What you need to do

Every Router has a Admin Page which can be accessed by any Browser Software. Do the Following to access the admin page of your router:

1. Get the IP of Router : Every device that connects to any computer network is allotted a  IP (Internet Protocol) address. This IP is used to identify a device on the network. You can understand this better if you visualise your colony. Every house has a unique number, so that you are able to identify it. Same is done on the network by means of IP address. They are written in this form 192.168.0.1 i.e. 4 octets. They all have a different meaning and I will not cover that in this article.

The easiest way to know the IP address of your router is to ask the supplier. But you can easily know it on your own. Connect your Laptop to the wireless Network.

First Method: If you see a computer Icon right hand side in the Taskbar for the wireless connection, double click on it,  in the window that opens select you will see 2 options on top i.e. General and Support. Click on Support and you will all the details here. The IP given under Default Gateway is the IP of your Wireless Router.

Second Method: If somehow wireless connection icon is not their in the status bar (which is possible) then follow these steps:
                                Click on Start->Run. Type CMD (hit enter)
You will see a new window with command prompt.
Type IPCONFIG at the blinking cursor and hit enter. This will show you all the details of all the Network connections here. Under Ethernet Adapter Wireless Network Connection you will see same details of the IP address. The Default Gateway is the IP of your wireless router.

2. Connect to Router: You can open the Admin page of your router while connected to the router as wireless client also, but this is not recommended. The other way is to use a network cable to physically connect Laptop or computer with the router.

How to connect?
Their are 2 ways as mentioned above. Connecting via wireless is simple and most people know. Connecting via cable needs more configuration and I will explain that below:

Steps to be followed:

1. Connect the Cable in the Network slot of your Laptop and the Other in the Network Slot which are given at the backside of your router. Please make sure that you do not connect this cable in the slot marked INTERNET.
2. A Icon with 2 computer connected will be showing in the bottom right side of the Task Bar. Double click it. In the window that opens click on properties.        
3. In the window that opens select Internet Protocol (TCP/IP). Double Click it.
4. A new window will open. Select "Use the Following IP Address". Here you need to manually enter the IP Address and other details. If your routers IP Address is 192.168.1.1 then type 192.168.1.2 i.e. change the last octet to any number between 2 to 254.
5. In the subnet mask type: 255.255.255.0
6. In the Gateway: type the IP address of the Router which you found by procedure mentioned above.
7. Click OK in all the windows.

Once you are connected to the router by any mode. follow these steps

                         Open Internet Explorer 
                         Type http:// followed by the IP of your router
                          Press Enter

This should open the login page of your router. All the routers comes with default username and password. Ask the person who has connected the router and configured the Internet if he has changed the password or not. If not then try these: user name: admin password: admin, or both as blank or username: admin and password blank. Actually this depends on manufacturer. But only these combinations are used.

This will bring you to the first screen of the configuration menu. BE CAREFUL: DONT CHANGE ANYTHING ELSE.

Locate the Wireless Options. Under this menu you will see 3-4 options. One is basic settins where you ae asked to define Wireless Network Mode, Channel etc. In this change Wireless Network Name (SSID) to something that you may like. SSID is the name which you see in the list when your laptop detects a wireless connection. This should not be default.

You will also find another sub menu under wireless Security or Wireless Security. On tis screen you will see Security Mode. Open the Drop down box and select WPA Pre Shared Key (few older routers may not have WPA) you can also select WEP but is considered less secured and can be
cracked easily. 

Once you Select WPA Pre Shared Key, few more options will be visible. Under WPA Algorithms Select TKIP. Under WPA Shared Key, type atleast 25 characters (mix of numbers and special character to make it strong). This key will be used to connect to wireless network i.e. any computer wanting to connect to your wireless network will be asked to provide this key and only then it will be allowed. After typing the key copy it and paste it in a notepad file so that you dont forget it.
Click on Save settings.

Now Select Administration and under Router Password change it. This is the pasword which is required to access the Admin page of the router. (Note it down).

Save and Exit. Few routers require that they should be restarted before setting could take effect. The menu options could vary from router to router. You will need to explore a bit to understand it fully. PLEASE DONT CHANGE ANY OTHER OPTION.

Now disconnect your laptop and connect to your wireless network. It will ask for the key. Copy the key from the notepad file (you wll need to copy twice) and click on ok. Thats all done. Please remember by default the key once entered to connect is saved by the laptop. so next time it will not ask you to enter. Few routers may confirm the key the second time you connect.

Few Tips Regarding Routes:

1. If you want to see who all are connected to your wireless network then Select Status ->Local Network->Click on DHCP Client Table. A new windo pops up and will show you all the people who are connected to your network. IT IS ADVISED TO CHECK THIS RANDOMLY so that you are aware who is trying to use your network.
2. You can Enable Logs. The Option is their under administration. It will take up space inside your router. Make sure they get deleted after you have checked them.
3. You can Reset your router to factory default. A push button is given behind the router and reset will be written. But be very careful as this will erase all the settings and they need to be done again. This is useful when you have forgotten your password and you canot access your router.

I have used the menus for linksys router. but they will be different for other makes. I request you to kindly explore your router a bit. The user guide should be their on the CD that came with it.