An all over face brush - This brush can be used to apply pressed or loose powder, powdered foundation, blusher, bronzer etc. I use it to apply powder to my face all over, its a really easy brush to use but if you dont have a brush or are saving up to buy say a MAC 150 then you could also use a powder puff to apply your powder or a kabuki brush. This brush is just a random one that I've had for a long time and doesn't have a company name on.
A angled brush - I use this brush to apply blush and to contour the face, using an angled brush makes this so easy that you don't really have to do anything as the brush hugs your face making sure that you get an even distribution of the colour. This is like the MAC 168. Mine is from Avon.
(sorry its dirty, i'd just used it and forgot to wash it)
An eyeshadow brush - This is a great brush to pack the colour onto your eyes so you don't have to keep reapplying. I really like this brush and only really use it to apply my eyeshadow. It works really well and if you cant afford to get lots of brushes straight away then this is the one to start off with :) This reminds me of the MAC 217. Mine is from No.7 and featured in this haul :)
These for me are the three to start your collection with and then work your way up to things like a concealer brush, a foundation brush etc. etc. because for those you can use your fingers until you get the right brush for you :) Hope this helps anyone whose wondering where to start :)