Download the image of your choice or build Storij from source and write it to a medium. In Linux use xzcat to write the OS to a flash drive or a microSD (for example for Raspberry Pi 3). On Windows, first you must extract the image using a tool like 7zip and then you can use Win32DiskImager to write the OS to a removable drive.
Your own PC or laptop from which you want to connect to the Storij-WebUI needs to support mDNS. For windows you may need to install Bonjour Print Services and for Linux you want to install and enable Avahi service. If you would like to use UPnP, it will require you to enable it in your router, or you will have to manually do portforwarding. If you are using the VM image, make sure that you have set up the network bridge and a DNS daemon like dnsmaq accordingly.
Use Google Chrome to connect to http://storijos.local. If Chrome initiated a search instead of going to the UI, you would need to exactly write http:// before storijos.local. You will be greeted with a page which will ask you to choose your timezone and enable 2FA.
Once you complete the 2FA setup, you will be redirected to the login page where you can log in using "storijer" as the user name and a token from your authenticator app.
After you log into the UI, choose your favorite chain and then open a WebShell. In the WebShell, login as root by typing "root" as the username and "storijos" as the password. Change the password for "root" and the user "storijer" by typing "passwd root" and "passwd storijer" respectively. If you would like, you can change the username as well.
Now you are ready to start hosting by setting up your favorite chain. Attach a drive to the device or VM and setup Sia or HyperSpace on it. You can choose to bootstrap the chain, or download a pre-verified layout. After the setup is complete you can initialize your wallet using an existing seed or a new one and unlock your wallet for the first time. If the WebUI became unresponsive during the first initialization or unlocking, it means the chain is doing heavy IO. You can either wait or re-login to the UI.
Depending on your internet setup, you can choose dynamic DNS, static IP or a domain name for your host. Then, In the "hosting" tab of your favorite chain, you can prepare and add storage from the attached HDDs/SSDs. Finally, unlock your wallet and change the hosting settings (if necessary) and announce your host.
In the next step, enable auto-unlock for your chain so that your host always stays accessible (in case of a reboot). You can sweep a seed, change your host options, change the hostname if you want to add another Storij machine to the network, or even setup another chain.