Posted: 18/01/2015 at 07:39
Hi Thomas and welcome
The first thing I'd say is with vegetables, grow things you like to eat - it may be obvious but you'd be surprised how many people I've known who grow swedes or spinach for example, but hate the stuff.
If you like beans, dwarf french beans are ideal for growing in raised beds - you sow them in April/May time. They're pretty straightforward to grow and will give you a good crop quite quickly, so they're encouraging for new gardeners
Runner beans are more tender (that means they will die if they get frosted) so you plant them out in late May/early June depending on whereabouts in the country you are and when you get your last frost. However, you can start them off in pots in your greenhouse where they'll be protected from frost. Runner beans need to climb so you'll need some tall bamboo canes (6-7ft) or similar to build a frame for them to climb up - the simplest way is to build a wigwam tied at the top and then plant two beans or bean plants at the bottom of each cane.
Do you like salads? If so some lettuces would be easy to grow (but you will have to keep an eye out for slugs as they like them too). I don't like to use slug pellets in my garden because they harm wildlife so I trap the slugs in yoghurt pots of beer - they die happy!
If there's someone in your household who likes cooking, you'll be very popular if you grow some herbs - chives, mint, parsley, thyme are all good to start with and can be bought quite cheaply as small plants from the garden centre in the spring.
As for the flowers - are you wanting flowers to pick for the house?
And as for roses, with the greatest respect to Perki I have to disagree about the soil - you don't need to buy ericaceous compost in for them, they're perfectly happy in most garden soils in the UK. https://www.rhs.org.uk/advice/profile?PID=153
However there are some plants that do need acidic soil - eg rhododendrons - so if you're buying plants it's best to check the label carefully or ask someone who knows.
At this time of year I would weed your raised beds and dig some well-rotted farmyard manure into the soil - you can buy it in bags from the garden centre.
Another useful thing to do now would be to get some pallets and make a couple of compost bins http://www.gardenersworld.com/how-to/projects/basics/how-to-build-a-compost-bin/87.html That way you can turn garden and kitchen veg waste into compost and in the future you can use that to improve your soil rather than having to buy so much compost and manure in.
And yes, now's the time to get your greenhouse repaired and shipshape - I don't have a greenhouse in this garden, so I'll leave that for others to tell you about.
And one more thing - start to encourage birds into your garden - they're the gardener's friends and will help you to get rid of the slugs and aphids that can attack your plants - so hang up some peanuts and birdseed for them now and they'll start to regard your garden as their territory and a place where they can find food and in the summer they'll come and eat the aphids for you
Do feel free to come and ask us questions - we like to help and nothing is too simple or straightforward - the only daft question is the one you didn't ask.