Hi guyz

Currently i use a simple system with MikroTik RouterOS.

Now I want to purchase a Router Board, but a little bit confusing to selecting that which is better for me...
please guide and help me.

My requirements is...
1. 24/7 ON
2. 100 Users
3. Load Balancing Feature (I have 2 WAN Connections)
4. Good Stability In Every Condition
5. Plug & Play
6. Low Cost But More Performance...

I would go to RB1100AH

some other person guide me about my specs to choose RouterBoard...

You need to be more specific on what services you will run before anyone can give you a better indication on what you need. Will you use simple queues,, queue trees, FW, bridge, meta router, PPPoE and so on? Whats the expected WAN connection speed per user and in totat?

I Need PPPoE Users with maximum 2Mb speed...
Simple Queues are recommended...
Wan connection speed is 10 Mbps or 20 Mbps...
Currently
Wan1 = 4 Mbps
Wan2 = 1 Mbps

I Need PPPoE Users with maximum 2Mb speed...
Simple Queues are recommended...
Wan connection speed is 10 Mbps or 20 Mbps...
Currently
Wan1 = 4 Mbps
Wan2 = 1 Mbps

easy, head over here: http://wiki.mikrotik.com/wiki/Manual:TOC

and read on.