Go to this link and read on the setup
http://www.mikrotik.com/docs/ros/2.8/ip/hotspot
or run the setup and follow the info below and punch in your own figures to correspond to your network
[admin@MikroTik] > ip hotspot setup
hotspot interface: ether1
local address of network: 192.0.2.1/24
masquerade network: yes
address pool of network: 192.0.2.2-192.0.2.126
select certificate: none
ip address of smtp server: 0.0.0.0
dns servers: 192.0.2.254
dns name: hs.example.net
name of local hotspot user: admin
password for the user: rubbish
[admin@MikroTik] >