I bought a leasehold property at auction, freehold will be easier :)
Make sure you get the 'pack' and read through it thoroughly, I actually had a solicitor do so too - I felt it was money well spent.
Everyone tutted A LOT about how little time there was to get things done. I just smiled a lot and said 'Yes, but that's life
'
Auction company wont give a rats arse if you have a mortgage are paying cash or if you have to sell your kids to raise the money, so long as you have the non refundable deposit on the day!
I had the mtge in place before the auction started
You need to take the deposit bank cheque (check with the auction company but it's usually 10% of the sale price but as you don't know what you will pay, they're pretty flexible as long as it's a reasonable amount of money.)
Sale room isn't scary, full of a right mix of people
Bidding is fun - no way would I have let anyone else do it
But if you do, I'll come and do it for you!!!
Decide on your maximum bid before you go.
Then decide how much over that you will actually be prepared to go to 
Bridging loan.... you are taking your life in your hands doing this, I wouldn't do it. You just never know - for some reason unknown to you, the property may be unmortgageable - then you are fucked. Just keep calling the lender/mortgage broker and chivvying them along!