Rigging screws and toggles

[Bob of Wight]

Hello Forum Members ... I have just signed on to this forum hoping to learn from others about Rigs and Rigging. I probably won't have much to say as I know very little about the art of Rigging other than my use of it when sailing ... which I have been away from for far too long.
Have been working on a boat for longer than I wish to admit, currently finishing a Hull & Deck kit, hoping to have it finished for 2011

I do have a couple of questions in the Rigging department ... (1) ... When determining length of new standing rigging: At what 'basic' length should the Turnbuckles be? eg: Maximum adjusted length? ... or partial? ... If partial, what percentage of adjustmant?
(2) ... Which to use ... Toggles with Fork/Fork turnbuckles or, install T-bolt toggle ends?
Oh, yes, one more: Which way is up? LH thread or RH thread ... I'm thinking LH ... Right is tight Left is loose ...