That fact that you are asking these basic questions,tells me you may not be ready to summon any Demon at this point.It is very important that you be dedicated first of all for you to protect against anything negative happening in this summoning,plus you need to be astrally open.Many people you find the JoS site have found it because they were looking to find how to summon a Demon(which the think is physical and they are not)or to do there bidding( and that is abuse that they will not tolerate).So please read up more on the how's and why's more before you dishonor our most loving and considerate Gentile Gods.And if you are all ready dedicated,then you have my apology but are you still ready is something you might want to consider asking yourself. Hail Satan
Brian
When calling on the Gods, it is best to use their candle colour as listed on the JoS website. However if you cannot gain access to said candle, whichever you can get that is closest will suffice. If you can buy the right candle, but you're just too lazy not to go and get it. Then you should reconsider and go and buy it (if you can).
Make sure when summoning the Gods, you have a true purpose and not just wasting Theirs and your time. The Gods are very busy and don't need to waste time on people summoning the Gods for kicks or to 'see what its like'.
Furthermore, before summoning the Gods it is good to be astrally open. Often times, newer members will Summon the Gods and then get no results, or so it seems to them. This is because they are not open enough to hear/see/percieve the Gods or their answer/reply. If and when you do summon the Gods, be open and keep an eye out for signs.