Time to plant?

Depends what you mean by 'cultivating'. If you mean digging out weeds or turf, then you can do that any time - tho best to wait for the soil to be not too wet as tramping about on it will cause compaction. If you mean digging in organic matter, that is usually done in the autumn, but you can do it anytime really. Try to avoid unnecessary digging as this can cause damage to the soil structure.

Re bulbs - most bulbs are planted in about November to flower the following spring.

Re seeds - now is the time to do those! If they are not hardy species, then wait untill risk of frost is over, but hardy ones can be sown now.

Re perennials and seeds together - that is absolutely fine. In fact, it is a good idea to 'fill out' a perennial border with annuals for the first couple of years before the perennials fill out.

Hope this helps!

There are also summer flowering bulbs and corms and you could plant them now - such as Gladioli and Lilies and others from your Garden Centre, either into pots or straight into the garden. Mark where you plant them, though! It's all too easy to dig them up by accident...lol

Thanks for the help! I really appreciate it and think I will actually plant some lilies and dahlias! Take care!

For both new and experienced gardeners it is very easy to spend a small fortune on the garden. Of course experienced gardeners are more likely to know which plants are suited to their garden and which to avoid
Woolworths stores have a reasonable range of perennial plants and bulbs at the moment and have several special offers and reductions. For seeds I would recommend Wilkinsons, some of their packets are less than 50p. Both stores tend to sell easily grown plants , but do check the instructions on the packaging.
You may find these websites useful places for basic information clearly presented:
http://www.bbc.co.uk/gardening/basics/techniques/growflowers_buyplants1.shtml
http://www.gardeningregister.co.uk/