I have a cable modem and I connect it to my laptop via the Ethernet cable. If I connect that ethernet wire to the LAN port in the WiFi modem, will I be able to surf internet on my laptop by connecting to WiFi access point?
Shouldn't be a problem. I had the same setup up until a few days ago. I'm in the UK but the theory is the same.
I connected to my seperate Belkin Wifi router from my laptop with an ethernet cable and I put it into 'AP Mode' (Access Point Mode). What this does is it serves as just an access point. I gave it a name (SSID) and a password and then connected it up to my cable modem using an ethernet cable.
The cable modem should be running DHCP. To elaborate, if you can connect to the internet without allocating an IP address to any of your devices then your modem will be running DHCP so nothing will need to be changed there.
Actually, the router will come with a setup wizard to walk you through it. It is very common these days. The cable modem Ethernet cable will connect to the WAN port on the router. This will allow the router to share the Internet connection with computers connected via wired or wireless.
D-Link has simulators so you can take a look at how the administration of the router works. Just scroll to find the router you are using or thinking about buying.