16024,
I'll try not to repeat any of the good practical advice given by all the responders so far. so here's a few ideas to get you thinking,
It's still time enough to start digging and do some planting, though the best time to dig is in the winter, to let the frost break down the soil. What type of soil do you have? Adding compost or farmyard manure will help build up the fertility. Knowing the soil pH would be useful too. All the brassica crops (ie cabbage, cauliflower, Brussels sprouts) like a limey soil (easy to achieve by adding lime before sowing).
Start small for now, what veg do you like or buy regularly? As was said previously, don’t grow veg that you don't really like, it will just rot sitting in your garden.
Get yourself a good gardening book, that deals with most aspects of vegetable growing.
Get some seed catalogues, Suttons (
www.suttons.co.uk) and Thomspon and Morgan (T&M) (
www.thompson-morgan.com) will send catalogues (and seed) to the Republic and are a good source for quality seed. They’re also full of good information about soil requirements, planting etc etc. T&M website is certainly worth a look. Surf the net for some good gardening websites, ie BBC gardening, RHS. Build up your knowledge as you go along and build up your confidence. even the best gardeners will have crop failures. So don;t give up if something goes wrong! Stick at it!
I buy all my seed online, as you're always sure of the freshest seed and not seed that has been lying around in a shop unsold from last year. Buying poor quality or cheap (within reason) seed is a bad investment.
Start with some easily grown veg (assuming you're like them) Salad crops like lettuce, scallions (grown from shallots) and maybe radishes are easily grown. Try some onions (from sets) too, Consider some carrots, maybe cabbage. Maybe get some strawberry plants. If your space is limited, I think stick to veg that crop several times in a season or what you would use on a regular basis like lettuce, scallions and carrots.
IMO, for a small garden, I'm not convinced of the merits of growing potatoes. You wait all summer for just 1 crop, certainly worth the wait but buying a few kilos of organic spuds in your local supermarket makes just as much sense and you could put your veg patch to better and more productive use.
Buying plants for transplanting into your garden is a good idea for this season, you can sow some seed for your own plants early next year inside.
Try some herbs, like parsley (slow to germinate, need to soak your seed), chives, mint, dill, basil. The seed companies mentioned sell "seed discs" which is a small disk with the seed attached, just put it in a pot of compost and cover it and water it and wait for it to grow. For the future, think about setting up a nice herb garden near the back door, or in a window box.
Consider sowing some carrots using a Seed Tape, this is like a roll of masking tape with seed stuck to it, just unroll it in a shallow drill and cover with soil. No thinning needed and great as thinning attracts Carrot root Fly.
Consider making your own compost, very worthwhile and environmentally friendly aswell. Easy to do, using your kitchen waste, teabags, egg shells etc. Great for building up your soils fertility and mulching shrubs etc.
Since you're garden should be relatively pest and disease free, try your best to keep it that way. Easier said than done! As mentioned already, learn the importance of crop rotation each year. Be very wary of bringing in soil from another garden, even if you’re getting it for free. The two things you don’t want to bring into your garden, is Potato Root Eelworm and Clubroot. Both will survive for years and make it almost impossible to grow potatoes and any brassica crops successfully.
Those a just a few quick ideas, feel free to contact me if I can be of any help,
Good luck with the gardening,