Service Web Site, Online Tool ?

How to start Service Web Site ( Online tool) ?

I have big idea and very interested to start Service Web site (Online tool)
But I'm not have enough knowledge about this methods.

I found after Google following Onlin Web services.

Online Text Tool(text split, Text marge, line break, etc)
Fint Font by Image
Fakenamegenarator
Facebook MP3 Share
Phone Number genarator
Domain Name genarator
YouTube2Mp3
Torrent Dirrect Download service
PDFtoDOC coverter. Doc to PDF
Online file converter/Password remover
Age calculator
Image resize and edit


But I like want help from you find trend at these day.

I think you will not ignore my thread and suggest me some cool ideas.

Thanks

You say you have a big idea but then asking others for ideas ?
Seriously I think you need to start smaller or hire somebody to help you out.

Yes, Have ideas, But don't know How to start and trend at this season?

and I'm glad if can help about Cost and resource requirements for the online web service?