In terms of connectivity, you really shouldn't bother trying to offer hosting services from your own premises - the typical home/office broadband connection won't sustain much (particularly upload) and it's often against the terms which could see you easily cut-off.
In any case, there are many other benefits of putting your hardware in a datacentre - such as security, remote hands, UPS/generators, air con. etc.
So on the assumption that you were to buy everything and colo, then you'd be paying a datacentre and (potentially) a separate transit provider with their kit in the datacentre in question - some datacentres are owned/operated by a certain carrier (transit provider), others are carrier-neutral... so it depends exactly where you go.
What you'd pay for would depend where you colo; you may pay for a monthly transfer limit (e.g. x GB/month) or you may pay for a certain amount of bandwidth (e.g. 5Mbps).
In terms of servers, you need to pay attention to the size/format... some datacentres you won't be able to colo anything but rackmount, others are the opposite - check costs of these things before buying a server!
I'd strongly recommend a respected brand such as Dell/HP etc. which will ensure reasonable build quality and an appropriate hardware replacement SLA.
In terms of Linux, you can't really go wrong with CentOS... it's basically an open source binary compatible version of RHAS.
For control panel, I'd (personally) recommend Plesk, but others to consider include cPanel and DirectAdmin... depends on which UI you prefer, cost, ease of management etc.
However, now forget all of the above and read whym's post - if you're just starting to offer hosting then you perhaps don't know enough to be managing your own hardware, and it'll cost you a lot. It will take time before you're taking enough each month to cover the monthly costs from it...
A VPS is a really good choice to start from in so many ways:
- the IP blacklist issue already mentioned
- easy access to management (a number of providers offer decent managed VPS plans - so avoids the need of finding a trustworthy third-party management company)
- very easy to upgrade as you grow - even without any downtime (although some providers don't support this, so check first!)
- maintain control of control panel software / versions and other important config / versions of things like PHP, MySQL etc.
