Where to start! So many Questions!!

Hi everyone. So im very exited to have got my allotment. Have started diggiing over so I can get cracking this year before it has a big makeover ready for next season. I am ready lots on here trying to find out the best way to do things but still have some questions!! I am a total newbie and only experiance is with tomatos last year!!

So my plan this year is to grow Runner beans, Carrots, Courgettes, Cucumbers, Spring onions Shallots, Radishes, Peas, Lettuce and some Rocket. (Blimey not sure im going to have enough space!)

Can someone tell me what i should get cracking with first and what varieties I should look out for? Also im looking around at buying seeds but there is a massive difference in price from people like suttons and people on ebay.

Heeelllllpppp!! 

Aldi are very cheap for seeds, normally starting around 30p-40p, but you have to get them when you see them, they dont hang round for long.

Radishes and lettuce grow really quickly so you can plant them in places you are saving for produce that needs planting later (believe they call it inter-cropping???)

I am presently sowing beans, peas, tomato, cucmber and leeks in pots/trays in the greenhouse for transplanting to the allotment later in the year and about to plant out in the allotment salad, onions, early potatoes, early carrots and parsnips.

As Nikkithefoot said it does depend on where you are in the country, so as a precaution I have saved some seeds and will sow some more in a few weeks this also staggers production.

Last year was my first year with an allotment (have grown at home previously) and I got a little carried away so my advice is do a little and take notes, then next year you will have a good idea of numbers, space and varieties. Good Luck