Future: Present continuous

The present continuous is used to talk about arrangements for future events.

There is a suggestion that more than one person is aware of (knows about) the event, and that some preparation has already happened.

Generally, when you use present continuous you have to include a time expression: tomorrow, at 9 pm, on January 2nd..

E.g.

a. I'm meeting Jim at the airport at 7:oo = and both Jim and I have discussed this.
b. I am leaving tomorrow. = and I've already bought my train ticket.
c. We're having a staff meeting next Monday = and all members of staff have been told about it.

http://www.oup.com/elt/global/products/naturalenglish/pre/a_grammar/unit08/nepre_grammar08_2/
http://www.oup.com/elt/global/products/headway/beginner/a_grammar/grammarunit14/hwy_begin_unit14_1/

(BE) GOING TO vs. PRESENT CONTINUOUS

We use both grammar structures for plans. However, the difference is the certainty of the plans:

(Be) going to= Intention

vs
Present continuous= Fixed plan

The future with "going to" can be used with plans and also future arrangements. This is the most versatile future form.

"I'm going (to go) to Egypt"

It can mean that I have bought the tickets and made the arrangements. It can also mean that I plan to go to Egypt, but have NOT made arrangements.

"I'm leaving for Egypt"

It means that arrangements have been made (you have called the travel agency, bought the tickets, booked the hotel). You really shouldn't use this form if you are talking about a plan.

English teachers often call the present continuous future form the "diary form" because you can use it for anything written in your diary or agenda.
Example: "Sept 23rd I'm seeing the dentist" <-- Fixed plan = arrangement
http://www2.cambridge.org/interchangearcade/launch.do?activityID=335&level=1&unit=15&type=Cup_word_up&stage=2

For more grammar explanation and exercises check this BBC link:
http://www.bbc.co.uk/worldservice/learningenglish/radio/specials/1530_gramchallenge32/
1. In the first part of the programme, they explain these general rules.
2. In the second part, they practise them with a foreign student: the teacher tries to arrange an English class with her.
3. You can print the written explanation
4. There are two "Practice quiz"

WILL/ (BE GOING TO)/ PRESENT CONTINUOUS

WILL: sudden decisions, predictions, with expressions: I think, I know...
GOING TO: plans and intentions, predictions based on evidence.
PRESENT CONTINUOUS: fixed plans (arrangements), very near future

http://madridteacher.com/Grammar/John/future.htm
http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-6874.php
http://74.125.113.132/search?q=cache:n2JVSEJ3Bj0J:www.gimnazija-prva-os.skole.hr/dokumenti%3Fdm_document_id%3D152%26dm_dnl%3D1+future+forms+exercises&cd=12&hl=es&ct=clnk&gl=mx&client=firefox-a