Welcome to the forum/hobby! As to magazines/etc., I think this forum is really all you need. There are some great magazines out there (includes the Britains one), but this forum is free and has way more pictures.
As to suggestions of companies that are more competitively priced, here are some:
Del Prado: this is probably the cheapest, and the figures are generally sculpted quite well and painted to a decent standard. The one issue is that they rarely have multiple figures from the same regiment. If you want to learn to paint and modify figures, Del Prado pieces can be a great starting point, and there are MANY people on this forum who can help you step by step.
http://www.delpradousa.com/shop/category/period/american-civil-war/
Frontline Figures: these figures go for around $20, which is pretty cheap nowadays. There is a lot of variety, and they always produce a full compliment of figures for each regiment. The ones issue is that the quality is not quite that of most other manufactures.
http://www.frontline-figures.com/
WBritain: while not cheap, they are probably the least expensive of the principle 5 matte toy soldier manufactures. The quality is market-standard, and they produce a wide variety of figures.
https://www.wbritain.com/
I also think a big thing to consider when deciding on what companies/ranges/figures to purchase is how you want to display them. As I get older and amass more figures, I have discovered that it can be nice to do smaller displays of a few figures from a number of different ranges. This is certainly cheaper than large-scale dioramas, but it also allows you more variety in your collection.
Many people simply display their figures in glass cases. Others buy pre-made diorama mats/boards and buildings to display their figures in dioramas. Many also choose to create their own dioramas, often mixing in pre-made buildings or taking advantage of commercially-available diorama making products. Let me know if you are interested in making dioramas- I am sure both myself and others would be happy to offer advice.
Kind regards,
Sandor