Beginner looking to get a good entry level used bike

[geratheg]

I'm new to biking and want to try the sport but don't have a road bike to go on.
I live in a non-hilly area in Sacramento so I'm debating whether to get fixed gear or shifting bikes.

My budget is up to $350. I've read so far that brand new bikes for that price won't do much so I guess I can go for a used bike.

What size bike would be best for me? I'm 5' 11" and 190lbs.
What kind of good bikes I can get used and for what price?
What should I look for?

Also what accessories should I get after I buy the bike to maintain it? (Such as what kind of chain lube etc.)

 

[vspa]

you should look for a L frame or 56cm more or less, depending on how the frame is presented, those are the two options (for example S, M, L, XL or 48-52-54-56-58cm) your budget is low so i would shop in craiglists or ebay and cross your fingers for something good to appear, accesories include a helmet, patch kit, a pump