1 - Gardeners' World
The Gardeners' World site is pretty much the ultimate resource for someone new to gardening. The site features a great gardening calender with weekly tips and an extensive 'how to' section covering projects and problem solving. There's also a plants database detailing 100's of plants and flowers.
If you can't find the help you need from the main pages there is also a forum section, on which you can post those burning questions.
2 - RHS
This is a great reference site to any budding gardener, what ever your skill level. They have an excellent advice section which can filter down all their information until you find what you're looking for. They also have good quality video guides for most basic gardening tasks.
The grow your own section is very detailed and any gardener would find it useful.
Although this page hasn't been updated for a while, it's an invaluable gardening resource for a new gardener. The gardeners calendar will help you to plan your planting and will give you daily tips and tricks to help make your garden bloom.
There's detailed advice no matter what your gardening goals may be, from vegetable and herb gardening to aesthetic gardening.
4 - Love the Garden
Love the Garden is an extremely well laid out website, and a great resource. There is detailed growing and gardening guides and will as weed and pest control tips, as well as gardening product reviews.
This is more of news site but is still quite inspiring for a new gardener. The allotments news is quite interesting and is regularly updated.
This gardening calender is a useful monthly guide for the up and coming gardener. The planting / harvest grids are of particular interest.
7 - WikiHow
WikiHow is good at detailing the basics for growing food in you own garden and includes a great tips and warnings section.
8 - NI Direct
This is a government services site, offering advice on greener gardens, growing fruit and vegetables, and encouraging wildlife into your garden. The main focus of this site is on green gardening, or eco-friendly gardening.
9 - Gardening Advice
There is some good advice on this page, in particular the biological pest control section. The gardening calendar isn't as detailed as on other sites but is kept up to date.Unfortunately, there are a number of paid for resources on this site.
10 - About.com
This site contains a lot of useful information for a novice gardener, but in a very is quite wordy. Also, you need to be careful as it is an American site, so seasonal information is completely accurate to the UK.