This experience relates to a startup in 2005 that folded during the credit crunch (2008). I am now working on a new product suite whilst continuing to consult.
The Mortgage Portal was an online marketplace for mortgage brokers to find appropriate products for their customers. It started with an idea that I spent a month building in my spare time. I worked with a colleague (both of us consulting in the mortgage technology arena) to bring it to market.
I started with a flexible mortgage that I drew salary against - so £0 capital. We then went around hawking the idea to the marketplace. We met a lot of resistance from established players (owned by the big banks, so no way we could disrupt the marketplace), and in the end pivoted into a platform for new lenders to get to market quickly. We helped a handful of banks launch new channels in a few months, which was a great selling point. Then came the downturn.
Our sales model was monthly fee + per transaction fee. It was never profitable.
We didn't look at grants/loans. There are some around, but my opinion is they are probably a distraction at this stage. If you're interested look at http://www.j4bgrants.co.uk/ - they have a wealth of information.
The most valuable thing we did was pivot. We didn't pivot fast enough which made things untenable.
We never scaled (started with two, ended with just me), and we failed for various reasons. I could blame the market - all our remaining customers either went bankrupt or closed within the space of a few days - but the reality was that the idea was just a starting point and we didn't move from that.
In my view, if you have an idea, your first step is to go out there and find a customer. Don't build anything (that is the easy bit) before you have someone willing to give you money. We should've done that - taken the idea and then asked what our customers wanted to do with it - rather than impose our views on them.
As for resources, there are many available and it will depend on what your trying to achieve and where you're located. If in London, I'd recommend the Google Campus (http://www.campuslondon.com/) as a good starting point. Then look for Meetups in your area.
Good luck.