Where is a good start off bar in bangkok early evening to sit out in the sun chill out chat etc cheep beer and option for food

The only choice and by far the best is the Bermuda Triangle of Morning Night, Big Dogs and the Golden Bollocks bar at the entrance of the Nana Hotel.

Got to agree with Rolly on this one. I like the rail at BD if you've got a mate or two otherwise its into Morning Night for some rock music and a few games of pool. Beer around Bt95 I think is the order of the day. Girls asking stupid figures and BFs into Bt500/600 territory from the bars but .........

Food options limited but Subway is around the corner and carts on the street.

Where are you staying ?

Depending where you're staying Si but another place is Soi 7 biergarten and the food court opposite and another place I go to is for takeaway proper English fish and chips or pie and chips and sit outside one of the bars in Soi Cowboy watching the tarts arrive.

Gulliver's Tavern on Soi 5 always works for me. Decent enough food, plenty of pool tables, they serve Beer Lao and have some tasty FLs at times too.

The Cathouse bar, ist floor on the left at the entrance to Nana Plaza, has a happy hour that runs from 4 'til 6.30 or 7. Local beer, all you can drink for about 150 Bht. Heineken is a bit more, maybe 200 or 250. It's only a small bar, directly opposite the Big Mango.
It's a good vantage point to see Nana gearing up for the evening.

Bier garten soi & i think

Bier garten soi & i thinkNever been a fan of the biergarten myself - just haven't ever seen many girls in there I'd take, mostly just a load of ropey old slappers.