Sir, i am using lan .i want to use this same lan to use it for two more computers.what are the possible ways to use one lan to many pcs.should i use hub or a router.what kind of hub or router should i buy/ help me

To use two more pcs, you can go for 8 ports switch, which can easily access with pcs and for a small network needn't to go for router and even hub also not in use. You can go for switch that is look like hub .

If I use a switch,will I be able to share internet without any probs.if it is possible,can I access internet simultaneously for two or more computers having only one internet connection

if i use a switch,will i be able to share internet without any probs.if it is possible,can i access internet simultaneously for two or more computers having only one internet connection

You must use a router for this. You can purchase a router with a builtin 4-port switch and wireless access point for about US$60-80.

Just a point here, a LAN is a collection of network devices connected together to share resources. So, if you already have a LAN you are connecting at least two devices. If you are sharing the Internet, you probably already have a router. Most routers do come with a 4 port switch built in. If you need to connect more than 4 devices, you can daisy chain another switch.