All depends on alot of things:
What sort of photography are you interested in; landscapes, sport, people?
What sort of level are you at now, do you know about shutter speeds and aperture, what about depth of field, or are you the proverbial blank canvas?
Where do you want to go with photography, do you just want to take good photos, it become your main hobby for the rest of your life or want to make money?
How much money can you afford to spend now - the absolute max figure?
But as a basic answer now is that if you know that you really want to "get in to photography" then an
DSLR will be the best choice. Assuming the DSLR route your choice really comes down to how far you are likely to go and if you are at all likely to taking things far then I would suggest buying in to either the Nikon or Canon systems as these give the best routes for growth in the future all the way to Pro. Your choice of system is effectivly an investment in the future opting for Nikon / Canon may cost a few extra £ now or you might loose a feature or two on your current choice of body but making the right choice now will save you money in the long term - there is nothing more costly than changing systems. I'd personally look at either a new or
second hand basic Nikon (e.g. D40 new or D50 S/H) or Canon (e.g. 400D new or 350D S/H) depending on what you can afford using as little of your budget as you can on the body and spending the greater portion on the lens (lenses are again an investment - a good one will remain useful much longer than the useful life of DSLR bodies).
Of course if you are unlikely to ever think about turning pro or wanting Pro level kit then you can also consider the offerings from the others DSLR manufactures (Sony, Pentax, Samsung, Olympus) as you will almost certainly get more features for your money, but you are less likely to find these S/H, as there is less of an upgrade path.
However, if you are just wanting to see if photography is really for you and/or money is
very tight then a secondhand "
bridge" type camera from ebay will allow you to have full control over all the important things like shutter speed and aperture so you can learn the basics on the cheap. The results from these won't be quite as good as a DSLR but if we are honest composition and technique are more important to a good photograph than the kit used. I've just had a quick look and you should be able to easily find a good example Fuji 4900Z for under £50 or the newer Fuji S9500 for around £100 both should come complete with memory card(s), cables, spare battery(s), etc.