I'm not sure where to post this so feel free to move it to where ever it belongs. Anyway, straight to the point - I want to start a small web hosting company for friends, clients and myself. Since I got a pretty good internet connection (100mbps up), I don't think I'll have any trouble with the connection itself.
I am worried about hardware, though. I don't have the money so get a great server and I've heard that using desktop hardware in a server is bad (is it really? I got a great computer with i7 920 and 6 GB DDR3 that I could use otherwise). My other option is to use my old HP-server that got 4 SCSI disks in RAID-10 and dual single-core old Xeon's. Would it be better to use my old server or my new desktop computer? My last option is to buy a new server. In that case, should I build my own or buy from Dell/HP/some company, and in that case, which?
So many questions - I hope you can answer a few of them at least.
First of all, I would suggest you to contact your ISP before digging into this as you will need to be able to buy dedicated IP's, and some ISP's will not allow you to do what you want. If they don't allow you to do the 2 above,I would suggest you to look at colocation, where your server(s) are placed in a datacenter, and you are allowed physical access.
Second, you should use server hardware for servers. After all, it is best to use the hardware for what it is intended for. At least in a production environment.
What lakridserne said. Most residential Internet accounts block port 25 (smtp mail) in both directions, and port 80 (html) outgoing traffic, among other ports. You could get a business account but it would be pricey compared to a residential account.
Your next option is to colocate your server machine in a data center, which will come with a commercial Internet account with no blocked ports. That's usually somewhat less expensive that a business Internet account.
What most small hosting companies do is get a VPS (virtual private server) account to use as a hosting server, which includes a connection to an unblocked Internet account. A VPS is an account that leases an isolated portion of a server hard drive where a dedicated operating system in installed. You can reboot your server, reinstall the operating system, and even have root access. If you get a modest account for Linux hosting you can find service for around $5/month.
The VPS saves the cost of building a server machine. The fact is that for your needs you can maintain a VPS account for several years for less than the just hard drive for a server machine would cost. That's the route you should pursue.