It isnt normally overly difficult but you would need to decide first what type of software you would be using on your server i.e if it was a forum based web site i would use VBulletin, by far the bes in my opinion, then theres how much traffic you would exspect, this would determine your server, up to 500 members i would go with a cheepo £7.99 per month server if you exspect more than a 1000 members i would then choose between a VPS ( cost between £20 and £60 quid )or a DEDI (Dedicated server, cost about £100 and upwards for a decent one) depending on your member base, dont forget your domain name, something small and catchy that is easyily found when googled would help. i have mostly dealt with forum based websites TBH and theres plenty availible info from
vBulletin - Instant Community if this is the way you choose to go, if not maybe someone else could help you with other options :-)
p.s in my exsperiance choose a UK based web hosting company, i have had some bad exsperiances with ones from USA and such like and communication with them is terrible if you get a problem, especially with the time difference,for best reviews check out here
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and if you are planning anything dodgy such as warez always go Dedicated.