The Kitchen and bathroom are two of the rooms where you can spend an absolute fortune, fitting your own kitchen is not really that difficult, you will need help with the gas of course and fitting wall cupboards is a lot easier with two people!
Below are pictures of two houses of which I have fit the kitchens on my own.
Planning a kitchen is really not that difficult, there are many Online kitchen planning facilities where you just enter the size of room and where the windows and doors are positioned etc. Most of the large DIY stores and Places like MFI have free brochures which will help you decide which units to fit in the kitchen. I always try and fit as many 1000mm base and wall units as possible as these are normally the cheapest units!
Kitchen after renovation
Surprisingly this kitchen cost just a couple of hundred pounds as a friend was replacing their kitchen at the same time as they did not like the white gloss units, so most of the units were free. You can often pick up some real bargains on ebay if you are prepared to remove the units from someone else's kitchen!
The most important thing to remember when planning a kitchen is to take accurate measurements. You can then use a combination of all unit sizes to fill the space completely. One thing you should never do is try and fill a space completely with units, so for example if you measured between 2 walls and the gap was 3 meters, do not try and fit three 1000mm units in as you will often struggle getting them in. It is far better to leave a gap and then fill the gap with an infill.
Planning the kitchen correctly can save you plenty of time and money, try and leave the Sink and cooker where they are as moving these adds to the expense, ensure you have sufficient sockets before fitting the kitchen. Normally I would plan 5 double sockets above the worktop level and two double sockets below the worktop level for the washing machine etc. The hob is gas but the oven is electric and is fed from a FCU on a spur from the ring main.
You can be really cheeky and go to one of the well known DIY kitchen retailers and give them your kitchen measurements and get them to plan your kitchen, be sure to tell them exactly what you want or they will fill your kitchen with expensive unnecessary units!