Hi Bloomer
The thing to remember is that we have to allow for late frosts into June here. It can be so disappointing to have grown some beautiful seedlings in a mild spell, only to have them all frosted when it's too late to sow more.
Every part of Scotland has its own local climate so it's best to go along to your local allotments, or a gardening neighbour and see what they do. Although I am south of you on the edge of the Southern Uplands, I would probably sow later than you may get away with, just because we live high at about 1000 feet (I know that in other countries people would laugh when I say that is high, but it is when compared to the surrounding areas, where people can sow a couple of weeks earlier than I can). You will be able to see which plants people manage to grow outdoors and which they don't. For example here we cannot grow tomatoes, sweetcorn or climbing beans outside - they grow but they don't ripen. Try a variety of things too and see what you have success with and what fails. I find that because of the constant wet here some things such as onions grow ok but don't store well, and I have a mammoth problem with weeds because a hoe is only useful when the soil surface is dry and the weeds can be killed off by the sun.
It would be well worth your while to make a cold frame, which is relatively easy if you are handy with simple carpentry and can get hold of some discarded double glazed windows, or even
buy new safety glass. Keep your eyes skinned for someone having new double glazing put in and get your request in fast
This warm spell is most unusual - at this date for the last two years we have been under snow with hard frosts.