Configuration

Standalone mode

When you start OpenSim in standalone mode, it will ask you several questions at the console. The first set of prompts that start with "NETWORK SERVERS INFO", you can just hit return to accept the defaults if you will be running in standalone mode. The prompts that start with "DEFAULT REGION CONFIG" are where you need to start paying attention. Some are self-explanatory. Here are explanations for the others:

• Grid Location. OpenSim regions can be placed anywhere on a 65536 by 65536 grid. In standalone mode, it is safe to leave these X and Y locations at their defaults for the first region (additional regions will need different coordinates, of course).
• Filename for local storage. Safe to leave at default.
• Internal IP address; This should always be 0.0.0.0 (0.0.0.0 means "listen for connections on any interface", basically a wildcard)
• Internal IP port for incoming UDP client connection. You can make this any port you want, but it is safe to leave at the default 9000.
• External host name. If you will only be attaching to your sim from a SecondLife client on the same machine, you can leave this at the default 127.0.0.1. If you will be wanting to connect to it from a client on another machine, this should be the IP address or hostname of the machine you are running this sim on. N.B - It appears that this must actually be the External Host IP Address, not the Domain Name.
• If configuring "External Host Name" (you can use the host name is my experience) and running viewer and server on the same machine (or LAN when using wan-ip and port-forwarding) create a loopback

To connect to your new sim, start up secondlife with the following command line switches:

-loginuri http://127.0.0.1:9000/ -loginpage http://127.0.0.1:9000/?method=login 

This assumes you are running the secondlife client on the same box. If you are running it on a separate box, substitute the IP address of your sim machine.
To create a user:
type create user <first> <last> <password> <x_loc> <y_loc> in the server console.