The Meaning of Life, the Universe, and Everything.
Need more info on the system you're using (8gb of RAM is 'enough', more is better, but not necessary).
An external (or 2nd internal) harddrive is always a good thing for recording, because it puts less strain on the read/write speeds of your drive. (writing large video files while pulling large texture files for the game, can cause a bottleneck which will hurt recording)
Information I would need on your system to tell if it would record alright:
- Harddrive setup (Size & number of drives - and if possible, what type of drives)
- Amount of RAM (you said 8gig)
- Video Card
As far as hardware/software needed:
- Headset mic - I would recommend either the Modmic or shop around for a high-end headset (I don't like headset mics for the most part, they have definite limitations)
- Standalone mic - For new creators, I lean towards the Blue Snowball, it's a good balance of cost & quality, while not top tier, it definitely will deliver you professional podcast or better quality audio.
- Personal taste for the most part, though an important thing is to get a pair that are 'noise isolating' (whether it's ear buds or over ear headphones - if it doesn't isolate noise, you risk 'echo' in your recordings, especially at louder parts of the game)
You may need peripherals depending on your choices, such as a mic stand, pop filter, and Shock Mount, these vary on the type of microphone you get.
-- The best "free" option is OBS (Open Broadcaster Software), it requires a lot of fiddling to work, but can get results comprable to Bandicam.
-- Pay options include software such as Mrillis Action!, FRAPs, DxTory, and Bandicam (the 4 most popular, I use FRAPs, and swear by DxTory as well, Action! is gaining a lot of traction, but I haven't tried it, and Bandicam, for me, is the weakest of the 4... there are options in addition to these though)
-- If you don't have something like Action!, DxTory, etc. that can record separate audio tracks, then you'll want to look at an audio recorder, here the 'free' option is just as good as the paid options, so just download Audacity.
-- "free" options are quite limited in functionality, there are some popular ones you can find in the free software thread.
-- "Pay" options actually have a quite good variety of selections for price vs power. Personally, I recommend "Sony Movie Studio" (Vegas's little brother) for people starting out with LPs or youtube in general - it's the best balance of power and functionality of the bunch. If you stick with youtube long term, or move into more complicated projects (such as things requiring 10+ layers of video or audio tracks) you may consider upgrading (most powerful is Adobe's suite of tools, Vegas is second - but both of those are restrictively expensive).