Hi Glenbob,
No real problem about investing in S&P 500 , I agree with you that an ETF seems ideal, because of the low management charges , and Vanguard seem an excellent company.
You would need a Broker . I use TD Waterhouse ( [broken link removed] ) , and find them very good. They charge € 20 per buy or sell, and a quarterly charge if your stock holding with them is less than € 5000. They have no problem with buying any Vanguard ETF you may require.
I can give no advice as to best time to buy ( I wish I could !). You seem in a position to make a purchase ever month, which would average out purchase costs , and as you intend to hold long term , seems a very good method.
May I end on a note of caution, as you say you are totally new to investing.
A very basic principle of investing is to diversify in to various asset classes, such as shares, bonds, property, and cash. E.G. "not all eggs in one basket".
It is your money ( and your risk !) so only you should decide how much you should allocate to each class. S&P500 have done quite well recently , but there can be no guarantee this progress will be maintained. Generally , the trend should be upward, and as you intend to hold long term you should be happy with S&P500 --- but I would be wary of too much exposure to any asset class.
I would suggest investing some of your monthly savings into S&P500 , and investigating some other asset classes for the rest . give details of lots of other asset class ETF's, and is good for information. Don't forget that most of the web sites that offer information are trying to sell you something.
An excellent starter book ( although a bit old ) is "A random walk down Wall Street" by Burton Malkiel . Reading the posts on AAM is also very informative.
Finally may I wish you every success in your investment decisions. Nodo.