There's nothing really complicated about working out a diet it's just more about what NOT to eat.
However, what you've heard about eating 5/6 small/medium meals a day is definately the way to go with fat loss, providing of course your not over eating at every meal!
For instance, if you looking at around 2500 kcals a day and you have 5 meals then its 500kcal per meal, dont worry about being to specific but keep it ball park and under.
Example:
8.00- raw oats/bran flakes/weetabix with chopped banana and skim milk
11.00- Sandwich made from wholmeal/brown bread, salad (lettuce, toms etc) with tuna/mackerel/sardines/chicken/turkey
14.00- same as above or have wholmeal pasta/brown rice instead of bread (smallish portion of pasta/rice here so carbs aren't to high unless of course you have a very physical job).
17.00- eat a good carb/protein/fat tea, e.g chicken/salmon/turkey/lean mince, with potatoes/pasta/rice (keep these lower if sedate) and as much veg as you can eat.
20.00- if you dont do much in the eve and tend to just watch tv etc then you dont want much carbs in this meal so have a 300g tub of cottage cheese (or if you cant stand the stuff a pint of skim milk) and a handful of nuts/seeds e.g cashews/almonds/brazil nuts/peanut butter/sunflower seeds/pumkin seeds.
If you have slightly smaller portion sizes in the earlier 5 meals you could bung another in at 23.00, again keeping it lowish carb, and making sure the total doesnt exceed you usage. Check weight/measurements regulary and adjust portion sizes to suit.
If you eat this regularly you'll feel less likely to snack (if you have too then obviously fruit is a good option, less so after tea tho)
Keep portion sizes 500 and below (if you estimated to use 2500+ a day you will be in a deficit). Keeping carbs in check and maintaining a steady blood/glucose level by regular eating keeps the body in a higher body fat burning ratio.
If you find your not loosing weight then slightly lower meal portions.
Of course meal sizes are person specific because everyone has different life styles and burns different amount of cals per day depending on their activity, so if your finding that 500 kcal meals x5 is leaving you knackered and weights dropping of you then up the kcal as ideally you shouldnt aim for more than 2-4 pounds per week if your looking to keep the weight off.
The times above are only an example, obviously some people will get up earlier/later and won't be able to eat at certain points of the day due to other activities (mainly work!) Just try and aim for a meal every 3 hours or so when you can fit it around your lifestlye, it soon becomes 2nd nature once you have a basic routine.
As for foods not to eat, well there's the usual suspects, sweets/cakes etc, there's no harm in eating them now and again, just subsitute another part of the meal with equivalent kcal value. Try avoid "whites", bread/rice/pasta, they raise blood sugar levels far quicker than wholmeal/brown and have low levels of fibre. Another "avoid" is sugary drinks as its very easy to get in excess kcal in this way without realising your doing it, obviously waters best but if you want taste then look for low sugar cordials or coke zero and suchlike.
If you have any questions about anything above give us a shout, im by no means an expert but have spent a few years reading up on stuff and practicing what i preach!